UNIT 3: Cell Membrane

-50 to -200 mv

Inside is negative, outside is positive

voltage difference across membranes

Cations move into cell through gated channels

Sodium Potassium pump

2 K+ in and 3 Na+ out

K+ likes to go down its concentration gradient

K+ goes out

K+ comes back in (when less negative)

Affected by chemical force

protons pumped against concentration gradient

direction of the pathway depends on placement of protons

Helps H+ come back into the cell

Facilitated diffusion

Sucrose moves against concentration gradient

No energy needed to bring it back

Comes in with H+ when enters cell

Energy us coming from proton gradient

Gated channels

stretch gated - mechanical stimulus

Voltage gated

Charge of electrical voltage in cell

Cell starts growing and dividing

Gene is turned on or off

Cytokines

Cell moves (chemotaxis)

Differentiation

Proliferation (mitosis)

Metabolic activation

Apoptosis (kill itself)

Inhibit proliferation

Hormones

Death Factors

Survival factors

Development

Depolarization

Na+ comes into cell

Cell gets less -

Happens until threshold reaches (+62 mv)

Hyperpolarization

Inside is more negative

More K+ in cell

Na+ and K+ is used to reach threshold

Physical contact

Gap Junctions

plasmodesmata in plant

Desmosomes Junctions

signal receptors

Subtopic

Eukaryotes

Yeast

signals for cells to combine to one

Local signaling

short distance, have the receptor, target cell is close by

Long distance signaling

Cell signaling helps to bring activators

Combinatorial Gene expression

Hydrophobic

receptor is inside cell

Hydrophilic

Phosphorlyzes from ATP

Adds phosphate groups to tyrosine

Signal molecule binds together to form dimer

Kinase is activated and phosphorylation behinds

Relay proteins attach to the phosphate groups of the tyrosine to begin transduction

receptor is outside along membrane, receptor is polar

Channel Receptors

Testosterone Signal

Binds to receptor to make transcription factor

The factor binds to promoter to start transcription

Goes through phospholipid bilayer

Helps initiate proteins to be made for male sexual traits

Reception

Alpha, Beta, Gamma Subunits

Binds GDP to GTP

ligand binds to receptor protein

receptor activates and GDP is converted to GTP

Alpha G protein diffuses from the receptor and finds an enzyme

Once enzyme is activated, G protein goes back to GDP

G protein uses the enzyme, Phosphatase to remove the phosphate group from GTP to GDP

Transduction

relate molecules to a signal transduction pathway

Inactive G protein is activated carrying GTP

G protein binds to adenyl cyclase going back to GDP

Active Adenyl cyclase make cyclic AMP (second messenger) from ATP

CAMP starts transduction and then inactivate

Phosphodiesterase removes the cyclic component of CAMP through hydrolytic reactions

CAMP becomes inactive to AMP

Phosphorylate cascade

Adds a phosphate group from ATP to another protein kinase

the other kinase does same to another

Amplifies message until it reaches its target

phosphatase hydrolyzes the phosphate group to turn off kinase

Cell Response

cell responds to the signal

Electrical Synapse

Electrical current flows from one cell to another through gap junctions

Subtopic

Communication occurs through a neurotransmitter

The spaces between the presynaptic membrane of axon and post synaptic membrane of dendrite of the synaptic cleft

Neurotransmitter binds to post synaptic membrane receptor (ligand gated)

Ca2+ can go in

Ions go through membrane depolarization

Neurotransmitter ligands

Breaks down through hydrolytic reaction

Taken up by pre synaptic membrane

Does not enter post synaptic membrane

Histones are proteins, in which DNA wind around twice

Nucleosome- Histone + DNA

Histone Core

H2A, H2B, H3, H4 [no H1]

2 molecules of each histone

Forms a histone octamer

H1 is found outside nucleosome

Brings nucleosomes together

Helps form tight helical fiber (the next level)

Linker DNA is the strand of DNA not winded by histones

The tight helical fiber is formed into loops, which are held together by a protein scaffolds at the bottom

The loop domain then coils to form a metaphase chromosomes

All cells have the same genes

About 20% genes are expressed

Heterochromatin

Highly compacted

No genes expressed

Euchromatin

Less compacted

Genes expressed

Chromatin

Condensation silences gene expression

Proximal Control Element

gene are lowly expressed (basal)

Close sequences in DNA to the gene

General transcription factors bind to the site

Distal Control Element

Far sequences in DNA to the gene

Example: enhancers

May even be located in an intron

Specific transcription factors

High level expression

lens cell in eye

Activators

increase expression

Activators help to initiate high level transcription

Repressors

inhibits expression

Combinatorial Gene expression

Incorporation activates and enhancers for gene expression

Continuous/ Constituted Expression

High level expression

Expression ALWAYS ON

Regulated expression

Basal low level expression

Prokaryotic Gene Expression

Activators

Help increase expression above basal level

Repressors

Proteins help decrease expression

Operators

Activators binds to this sequence to start high level expression

Induced expression

Repressors does the opposite

Basal level expression

On or off switch of transcription

Terminator Sequence

The end sequence in which transcription ceases

Operons

Activators, repressors [operator, promoter & terminator]

Activators help with transription

The lac operon - both positive and negative

Repressor proteins inhibit transcription

The trp operon

The Lac Operon

Both + and - regulation

Found in prokaryotes like Ecoli

Gene Z

Glucose and galactose

Uses Enzyme B Galactose

Made by Gene Z

They breakdown lactose

Gene Y

the lactose goes through the transmembrane

The gene Y codes for permease

Gene Z

make transacetylase

Adds acetyl groups to lactose to make it easier for B GALACTIDASE to break down lactose

When lactose is available

Repressor is suppressed with allolactose

Contribute activator proetin (CAP) binds to operator

When there is high levels of camp

No presence of glucose

The trp operon

Tryptophan is synthesized

Operon is off when there is tryp

Operon is on when there is no tryp

Negative Regulation

Tryptophan functions as a corepressor

Binds to repressor protein

Repressor protein binds to operon

Operon is turned off

Cell grows nearly to its full size

Synthesis phase

DNA is replicated

cell finishes growing

most of the life of the cell is spend here (interphase)

Subtopic

cell finishes growing

more growth

prophase

Condensation of chromosome

Nucleolus disappear

DNA condenses

Chromosome structure appears

Microtubules appears from centrosomes in animals

Prometaphase

microtubules appear and attaches to kinetchore

Nuclear envelope is degraded

Kinetochore attaches to chromosomes in centromeres

Metaphase

Sister chromatids are ready to separate

Chromosome align at the center of cell

anaphase

The cell becomes bigger

Chromosome separate

Sister chromatids separate and move to the ends of the cell

telophase

Nuclear membrane reappear and 2 sets of chromosomes

Spindle fibers are broken up

Chromosomes uncoil and become uncondensed

Cytokinesis

Cell is composed by a contractile ring form microfilament

Cell is divided in nearly equal cells

Cleavage furrow is formed

Organelles are replicated

Gametes are formed through meiosis

Germ line cells produce gametes

2 copies of each chromosome in diploid organelles

Produces gametes

Haploid cells

1 copy of each chromosome

Cells are going through the interphase

DNA in the germ cells are duplicated before meiosis begin

Meiosis 1 (produces 2 diploid cells)

2 unique daughter cells that have the amount of DNA as parent germline cells

Prophase 1

DNA condenses to form chromosomes

Duplicated sister chromatids join together at the centromere

Each pair of homolysis chromosomes undergoes synapses to form a complex

Chromosome material is exchanged by the 2 parts of sister chromatids

Sister chromatids from each chromosomes are no longer identical

No two siblings aside from twin are genetically identical

Nuclear membrane begins to break down

Two centrosomes are present with microtubules -- kinetochores

Metaphase 1

Synapse chromosomes align at the equator

Align randomly

Different combinations

Anaphase 1

Homolysis chromosomes separate and migrate

To 2 poles of the cell

Sister chromatids are attached at centromere

Telophase 1

Cell divides into 2 daughter cells

Nuclear membrane reappears

Meiosis II: similar to mitosis (produces 4 cells)

Prophase II

Chromosomes condense and nuclear envelope breaks down

Centrosomes appear and forms kinetochores

Daughter cells have one copy of each hydrolysis chromosomes

No synapses or recombination

Metaphase II

Chromosomes align at equator of cell

Random alignment

Anaphase II

Sister chromatids are pulled apart

Microtubles shorten and ends of cells are aligned

Telophase II

Nuclear membrane returns

Cytoplasm is divided into 2 haploid cells (gametes) -- cytokinesis

Failure of CDKs cause cancer

disrupt and inavde issues

accumulation of mutants

no density dependent inhibitioln

oncogenes cause cancer

Tumor suppressor P.53 is mutated it can not do its job

If Ras is hyperactive a signal will continually be
expressed, never turning off

can be used to diagnose diseases

Down syndrome

Chromosomes 21 has 3 chromosomes instead of 2

Produce gametes

Meiosis

Produce haploid cells (1N)

cyclin dependent kinases ___ to phosphorlyze

They form CDK-cyclin complex

Density dependent inhibitor

Would not grown when mixed cut in environment

Forms single layer

Cancer cells

Doesnt exhibit any growth inhibitions

They propagate mutations

They establish their anchor in different plane

Forms tumor on top of each layer

A disease of signaling cycle

Oncogenes

Cancer causing genes

Proto Oncogenes

Are normal cancer genes

When mutated or muted can cause cancer - become oncogenes

Tumor Suppressor Genes

Suppresses cell division/ cycle

P-53

Pauses cell cycle

Transcription factor

Makes a protein that hurts gene expression

When there is a thymine dimer, p-53 is needed

If p-53 is mutated, there will be continuous cell division

have autosome (NON SEX) chromosome -

Body cells

2N diploid cells (one from dad one from mom)

Normally in G0 phase

Volcanic eruption was the source of molecules

redid experiment of Oparin Harding

Tried to recreate the environment

Ribozyme oldest organelle

contains RNA and protein

Hydrocarbons, hydrogen cyanide, amino acids

Archaea

halophiles

methanophiles

thermophiles

Has introns

Bacteria

Capsule

Petidoglycan - sugar coated cell wall

No nucleus

Plasmid

chromatin/somes

Pili- attachment for reproduction

Cilia - hairlike projections of the exterior of the bacteria, for movement

Flagellum

No introns

Coupled DNA rep and transcription

Has UNBRANCHED lipids, its saturated, because its rigid

Eukarya

Has nucleus- double membrane

Has envelope

Has lamina

intermediate filament,

helps with stability and structure of the nucleus

Chromatid in nucleus

Nuclelous

DNA

Lysosomes

has hydrolase

lysozyme

which helps engulfs and digest bacteria

break down macromolecules

phagocytosis

engulfs outside materials

autophagy

recycles organelles or any cell material

pH acidic

Peroxisomes

Produce Hydrogen Peroxide to form water! H2O2 to H2O

Form water

Vacuoles

contractile vacuoles

rigid, moving excess water out of the cell

prevents lysine when cell self-destructs

food vacuole (vesicle)

carries things for transportation

Central vacuole

found in plants, rigid

Mitochondria

Produces ATP

Cellular respiration

DNA and protein

Has a double membrane

Cristae

where atp and cellular respiration happens

Rough ER

Double membrane

Nucleus

Protein modifications

Glycoproteins

sugars in the rough ER

Smooth ER

Double membrane

Iipid synthesis

Detoxification

Golgi

Helps package proteins

Sends them out

Synthesis

Modification

Chaperones

2nd tag of protein

helps in modification and folding

Ribosomes

Free bound

Two components

rRNA and proteins

Translation

Cytoskeleton

Microfilaments

Transport/motor protein

myosin

Amoeba

Actin Monomer

muscle contraction

movement

Microtubules

monomer: tubulin

Alpha

Beta

movement

structure

cell division

Motor protein

kinesin

Found in flagella

Intermediate filaments

Nuclear lamina, keratin

Structure and maintenance, stability

fibers

Progeria

Junctions

Tight

No passage of the free nucleus

Intestines and skin

Rat = poison by opening the gap junctions

Gap/ Plasmodesmata

Allows everything to pass through

Desmosomes

Selected passage

Intermediate filaments found in here

Signaling

ECM

plasma membrane

-peripheral proteins - sodium, potassium ion channels

collagen

Bacteriologist

Looking for a vaccine for pnemonia

Streptococcus pneumonia

Four trials

S- dead rat

R- alive rat

Heat S - alive

Heat S & R- dead rat

There was a transforming principle!

redid griffith’s 4th trial

reinforced the transforming principle

test tube

didn’t prove anything

Used radioactive phosphorus and sulfur

RNA is not genetic material because it is unstable

this is due to the OH group in the ribosugar

PURE AS GOLD

Pyramidines - C and T

Number of purines = number of pyramidines

15% A, 15% T….. 35% G, 35% C

Always have to be 50% 50%. A& C= 50%... G&T= 50%

Watson and Crick

Made 3D replica of the dna

Discovered that DNA was a double helix

semi-conservative

polymerase chain reaction, all happens in the test tube!

Makes a lot of dna

artificial

Denaturation

Temp is increased so that hydrogen bonds can break and strands can separate

Hydrogen bond is broken

Both strands separate

Annealing

Temperature is reduced

DNA primers are added to parent strands through hydrogen bonds

Elongation

Temp is slightly increased

Tag polymerase (from archea) elongate synthetic DNA primers

dnTP

energy used in PCR TO KEEP ELONGATION MOVING

Oparin Harding theory

Volcanic eruption was the source of molecules

Miller Urey

redid experiment of Oparin Harding

Tried to recreate the environment

Ribozyme oldest organelle

contains RNA and protein

Hydrocarbons, hydrogen cyanide, amino acids

3 domains of life:

Archaea

halophiles

methanophiles

thermophiles

Has introns

Bacteria

Capsule

Petidoglycan - sugar coated cell wall

No nucleus

Plasmid

chromatin/somes

Pili- attachment for reproduction

Cilia - hairlike projections of the exterior of the bacteria, for movement

Flagellum

No introns

Coupled DNA rep and transcription

Has UNBRANCHED lipids, its saturated, because its rigid

Eukarya

Has nucleus- double membrane

Has envelope

Has lamina

intermediate filament,

helps with stability and structure of the nucleus

Chromatid in nucleus

Nuclelous

DNA

Lysosomes

has hydrolase

lysozyme

which helps engulfs and digest bacteria

break down macromolecules

phagocytosis

engulfs outside materials

autophagy

recycles organelles or any cell material

pH acidic

Peroxisomes

Produce Hydrogen Peroxide to form water! H2O2 to H2O

Form water

Vacuoles

contractile vacuoles

rigid, moving excess water out of the cell

prevents lysine when cell self-destructs

food vacuole (vesicle)

carries things for transportation

Central vacuole

found in plants, rigid

Mitochondria

Produces ATP

Cellular respiration

DNA and protein

Has a double membrane

Cristae

where atp and cellular respiration happens

Rough ER

Double membrane

Nucleus

Protein modifications

Glycoproteins

sugars in the rough ER

Smooth ER

Double membrane

Iipid synthesis

Detoxification

Golgi

Helps package proteins

Sends them out

Synthesis

Modification

B cells

secrete antibodies

carries golgi bodies

Chaperones

2nd tag of protein

helps in modification and folding

Ribosomes

Free bound

Two components

rRNA and proteins

Translation

Cytoskeleton

Microfilaments

Transport/motor protein

myosin

Amoeba

Actin Monomer

muscle contraction

movement

Microtubules

monomer: tubulin

Alpha

Beta

movement

structure

cell division

Motor protein

kinesin

Found in flagella

Intermediate filaments

Nuclear lamina, keratin

Structure and maintenance, stability

fibers

Progeria

Junctions

Tight

No passage of the free nucleus

Intestines and skin

Rat = poison by opening the gap junctions

Gap/ Plasmodesmata

Allows everything to pass through

Desmosomes

Selected passage

Intermediate filaments found in here

Signaling

ECM

plasma membrane

-peripheral proteins - sodium, potassium ion channels

collagen

Griffith

Bacteriologist

Looking for a vaccine for pnemonia

Streptococcus pneumonia

Four trials

S- dead rat

R- alive rat

Heat S - alive

Heat S & R- dead rat

There was a transforming principle!

Mckay & Mcleoud (M&M)

redid griffith’s 4th trial

reinforced the transforming principle

test tube

didn’t prove anything

Hershey and Chase

Used radioactive phosphorus and sulfur

RNA is not genetic material because it is unstable

this is due to the OH group in the ribosugar

Chargraff’s Rule

PURE AS GOLD

Pyramidines - C and T

Number of purines = number of pyramidines

15% A, 15% T….. 35% G, 35% C

Always have to be 50% 50%. A& C= 50%... G&T= 50%

Watson and Crick

Watson and Crick

Made 3D replica of the dna

Discovered that DNA was a double helix

Messelson and Stahl

semi-conservative

PCR

polymerase chain reaction, all happens in the test tube!

Makes a lot of dna

artificial

Denaturation

Temp is increased so that hydrogen bonds can break and strands can separate

Hydrogen bond is broken

Both strands separate

Annealing

Temperature is reduced

DNA primers are added to parent strands through hydrogen bonds

Elongation

Temp is slightly increased

Tag polymerase (from archea) elongate synthetic DNA primers

dnTP

energy used in PCR TO KEEP ELONGATION MOVING

e use both strands

In euk- 2 ORI

In pro - 1 ORI

DNA III - extends and proofreads

happens downstream

uses the template strand

Promoter

located upstream

TATA box

found in promoter

contains transcription factor which contains protein

RNA pol II binds because it needs transcription factor to bind

+1 sequence -

Poly A

signals the nuclease to make a cut at the mRNA strand

Ribonuclease

cuts the sequence at the poly A

Poly A polymerase

brings a bunch of As to stabilize

Splicesosomes

cuts out the introns

RNA splicing occurs before the cap is added

Initation

Small subunit ribosome

scans where it starts

Trna comes with anticodon, happens at P site

Large subunit ribosome attaches to the TRNA

Elongation

another trna comes in and puts another anticodon at the a site

Amino acid

synthases

connects the tRNA to the correct amino acid, reads it first inorder to use the enzyme

Steps:

small ribosomal subunit attaches

- scans for AUG codon

- tRNA attaches to the codon

- large ribosomal unit attaches to the complex

- this happens in P site

-tRNA comes into A site

release factor comes into this site

-the mRNA shifts in codon to P site then E

-release factor attaches to stop codon on A site

-hydrolysis reaction breaks the ribosomal complex

-translation is finished

happens in nucleotides of DNA

silent

1 nucleotide change

- no change in amino acid

Missense

1 or 2 Nucleotides

Change in Amino Acid

Nonsense

Early stop codon that stops translation

2 Membranes

Mitochondria

Chloroplast

Nucleus

Endomembrane system

ER- GOLGI- PLASMA MEMBRANE OR GOES BACK TO THE ER

Steps:

Free ribosome bound

Translation is done

Signal sequence is reached for signal peptidase to make a cut

The protein is now in the lumen of ER

The protein is modified to glycoprotein by chaperones

The protein is transported to golgi

The golgi further modifies the protein and packages it

The vesicle is sent to lysosomes, extracellular matrix, plasma membrane

harvest energy

light reactions gather energy and transfer it to electron carriers (NADPH is an electron carrier) or use energy to make ATP

NADPH & ATP is used to drive calvin cycle

-not make sugars directly

collection of proteins and pigment molecules

a ray of satellite dishes that tries to gather light

Photon hits the photosystem and hits the cholorphyll molecules and ultimately funneled by the reaction center (special chlorophyll molecules)

Reaction center is where the electron will be excited and ultimately lost from the chrolophyll, primary electron acceptor grabs it chlorophyll loses it

Act 1 :

Energy is captured by Photosystem II

H2O split into oxygen and hydrogen

Chlorophylls lost electron is REPLACED BY TAKING AN ELECTRON FROM WATER “splitting water”

O2 IS RELEASED AS A BY-PRODUCT

protons (from water) are released to thylakoid space (lowering pH) , used to drive the synthesis of ATP

Act 2:

Energy is transferred through Electron Transport Chain to Photosystem I

primary e acceptor passes it to ETC, uses energy to move protons against concentration gradient to move it into the thylakoid space

proton gradient is used to make ATP

Act3:

Photosystem transfers electrons, reduces NADP+ to NADPH

electron in that reaction center bounces to a higher state

this electron goes to a shorter ETC, then electron carrier NADP grabs the electron and becomes NADPH

Light reactions:

olar energy is used to make ATP and NADP not for cellular work but for calvin cycle

this is called NON- CYCLIC FLOW

Chemiosmosis

using proton motive force to generate atp

can be used to do work

atp synthases allows protons to move down their concentration gradient to produce ATP from ADP

protons are released from the thylakoid space

pumping of protons from the stroms to the thylakoid space using the energy inherent in the ETC

RESULT: HIGH PROTON CONCENTRATION BUILDING UP IN THE THYLAKOID SPACE

Mitochondria and Chloroplast similarities in Chemiosmosis

both cases, there is inherent energy and electron transport chain pumping protons across the membrane

Subtopic

Subtopic

Subtopic

both respiration and photosynthesis, rely on a proton gradient that is generated by the ETC as electrons move down their electron transport chain

ATP synthase uses proton motive force to phosphorylate ADP to make ATP

ATP is generated in the compartment where its needed

Mitochondria and Chloroplast Differences in Chemiosmosis

proton movement in both organelles.

Mitochondria

pump protons pump in the inner membrane gradient

Chloroplasts

protons pumped in the thylakoid space, (stacks)

where electrons are coming from that moved down from ETC and established the proton gradient

Photosynthesis

source of the electrons - the excited energy, higher energy state, is coming from chlorophyll molecules as photon hits a cholorphyll molecule that excites a electron and that energy is what is driving the generation of ATP

Respiration

the high energy electrons are coming from food as we break down like glucose that has a high PE which we use to make ATP

CO2 fixation

energy in ATP and NADPH is transferred into sugar, a more stable storage form

products of the light reactions except of o2 are reactants in calvin cycle

we need a source of carbon, so we use co2

carbon fixing reactions are light independent

Act 1:

co2 enters the cycle diffused into the leaf through the stomata and into the chloroplast, and its carbon is snapped onto a pre-existing 5 carbon carboyhdate by the enzyme rubisco

this makes a highly unstable 6 carbon molecule and breaks down immediately due to its 2 phosphate groups

Act 2:

ATP is used to phosphorylate the other side of the 3 carbon molecule, and 3 carbon molecule is reduced by NADPH to form one molecule of G3P

end of 2nd act makes the product

G3P is half a glucose, so far we have spent 6 atp and 6 nadph

need 3 more atp

End of act 2, we have 6 G3P, one will be released to make glucose ultimately and FIVE will continue

ATP becomes ADP

NADPH has been oxidized to form NADP (lost electrons)

ADP and NADP will return to the light reactions and get recharged

Act 3:

5 g3p CONTINUES IN THE CYCLE

basically be rearranged with the help of ATP to form a 5 carbon sugar and becomes a starting point ones again

another carbon from carbon dioxide attaches again, attaches to the carbon ribulose bisphosphate to make unstable 6 carbon intermediate and so on and so forth

TWO g3ps are needed to make 1 glucose(which was released in act 2)

and glucoses will quickly be assembled into starch

Respiration

Use energy (respiration)

glycolysis

Citric acid cycle

Oxidative phosphorylation

1st stage of Cellular Respiration with oxygen

Fermentation occurs when no oxygen is present

Glycolysis

Signal sequence is recognized by signal recognition protein (SRP)

Checkpoints include G1/S, G2/M, and M

Regulators include CDKs

phosphorlation occurs initating chain of events promoting transcrption

hit by photon of light that energy is transferred and funneled to the reaction center

Uses 2 ATP to break up glucose into 2- 3 carbon chains

each 3 carbon has a phosphate atachted to it

2 NAD+ are reduced to NADH with the addition of hydrogen

2 molecules of pyruvate per glucose and 4 ATP, Net 2 ATP are produced

enzyme hexokinase phosphorylates glucose phosphoglucoisomerase converts glucose 6-phosphate into isomer

Uses 2 ATP to break up glucose into 2- 3 carbon chains

2 NAD+ are reduced to NADH with the addition of hydrogen

2 molecules of pyruvate per glucose and 4 ATP, Net 2 ATP are produced

Covalent

Polar

Different Electronegativities

Dipole Dipole Interactions

Paritial negative

Partial positive

Hydrophillic

Hydrophilic Heads

Nonpolar

Similar Electronegativies

Hydrophobic Interactions

Cage Away from Water

Hydrophobic Tails

Van Der Waals Interactions

Separation of charges

Metallic

Ionic

Transfer of Electrons

anion

Negative Charge

cation

Positive Charge

Macromolecules are polymers, built from monomers

Large carbohydrates (polysaccharides), proteins, and nucleic acids are polymers, which are chains of monomers

The components of lipids vary

Monomers form larger molecules by dehydration reactions, in which water molecules are released

Polymers can disassemble by the reverse process, which is hydrolysis

no anchorage dependance

Subtopic

each 3 carbon has a phosphate attached to it

Carbohydrates

Carbohydrates serve as fuel and building material

Examples of carbohydrates

Monosaccharides

Glucose

Fructose

Disaccharides

Lactose

Sucrose

Serve as fuel and are carbon sources that can be converted to other molecules or combined into polymers

Polysaccharides

Cellulose (plants)

Strengthens plant cell walls

Starch (plants)

Stores glucose for energy

Glycogen (animals)

Stores glucose for energy

Chitin (animals and fungi)

Strengthens exoskeletons and fungal cell walls

Lipids

Lipids are a diverse group of hydrophobic molecules

Components of lipids

Glycerol

Consists of 3 fatty acids

Examples of glycerol

Triacylglycerols

(Fats or oils) -> glycerol + three fatty acids

Important sources of energy

Phospholipids

Consist of a phosphate head and 2 fatty acids

Glycerol + phosphate group + two fatty acids

Are lipid bilayers of membranes

Steroids

Four fused rings with attached chemical groups

Consist of a steroid backbone

Component of cell membranes (cholesterol)

Signaling molecules that travel through the body (hormones)

Proteins

Proteins include a diversity of structures, resulting in a wide range of functions

Consist of R groups (a type of amino acid monomer)

There are 20 types

Examples of proteins

Enzymes

Catalyze chemical reactions

Defensive proteins

Protect against disease

Storage proteins

Store amino acids

Transport proteins

Transport substances

Hormones

Coordinate organismal responses

Receptor proteins

Receive signals from outside cell

Motor proteins

Function in cell movement

Structural proteins

Provide structural support

Nucleic acids

Nucleic acids store, transmit, and help express hereditary information

Consists of a phosphate group, sugar, and nitrogenous base

Examples

DNA

Consists of:

Nitrogenous bases = C, G, A, T

Sugar = deoxyribose

Usually double-stranded

Phosphate group

Stores hereditary information

RNA

Consists of:

Sugar = ribose

Nitrogenous bases = C, G, A, U

Usually single stranded

Phosphate group

Various functions in gene expression, including carrying instructions from DNA to ribosomes

Genomes and proteomics have transformed biological inquiry and applications

Recent technological advances in DNA sequencing have given rise to:

Genomics

An approach that analyzes large sets of genes or whole genomes

Biofinformatics

The use of computational tools and computer software to analyze these large data sets

Proteomics

A similar approach for large sets of proteins

The more closely two species are related evolutionarily, the more similar their DNA sequences are

DNA sequence data confirm models of evolution based on fossils and anatomical evidence

Unbranched

Branched

compounds with same # of atoms of same elements but different structures and different properties

Structural

Cis-trans

cabons that have covalent bonds to the same atoms but differ in spatial arrangements due to the inflexibility of double bonds

cis isomer

2 x's on same side

trans isomer

2 x's on opposite sides

Enantiomers

L isomer

R isomer

Properties

High Specific Heat

High Heat of Vaporization

High Humidity prevents Evaporation

Denser as solid than

Expand when Heated

Contract when cooled

Solvent of Life

Stutural

Different Covalent Arrangements

Geometric

Different Spacial Arrangements

Enantionmers

Mirror Images

hydration shell

polar because of electronegative oxygen

forms H bonds with H2O

usually ends with -ol

sugars w/ ketone groups (ketoses)

sugars w/ aldehydes (aldoses)

acts as an acid

covalent bond between O-H is very polar

acts as a base

two -sh groups can react forming a "cross-link that help stabilize protein structure

contributes positive charge

affects gene expression when on DNA or on proteins bound to DNA