Categorias: Todos - gene - nucleus

por Bio 311C 2 anos atrás

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Biomolecules

Various cellular components and their functions play crucial roles in maintaining the structural and functional integrity of cells. Cilia, which extend from the plasma membrane, are vital for the movement of eukaryotic cells.

Biomolecules

Eukaryotic Cells

Bacteria

Gene Regulation

Turns off or reduces the expression of one or more genes by binding to the operator.

Regulate the transcription of genes; Bind to the promotor or enhnacer area of DNA.

Promote gene expression; positive regulation.

Extracellular matrix proteins: collagen

Serum proteins: albumin

Milk proteins: casein

Peptide hormones:Insulin

-Digestive enzymes: Amylase

Examples of secreted proteins

The nuclear envelope is connected to the rough ER which is also continuous with the smooth ER.

Membranes and proteins produced by the ER move via transport vesicles to the Golgi

The Golgi pinches off transport vesicles and other vesicles that give rise to lysosomes, other types of specialized vesicles, and vacuoles.
The lysosome is available for fusion with another vesicle for digestion.

A transport vesicle carries proteins to the plasma membrane for secretion

Endomembrane System

2 ways

-Both processes synthesis is completed on free ribosomes


go through organelles

chloroplasts

peroxisomes

nucleus

1st way: ER (inside of cell "cytoplasm")

Summary:

mRNA--> ribosome-> rough endoplasmic reticulum-->Golgi apparatus--> Lysosome--> Exocytosis

Secretory Pathway: path taken by a protein in a cell on synthesis to modification and then release out of the cell (secretion)

Targeting Proteins to the ER
Polypeptide synthesis begins on free ribosomes in the cytosol

An SRP binds to the signal peptide, halting synthesis momentarily

The SRP binds to a receptor protein in the ER membrane, part of a protein complex that forms a pore.

The SRP leaves, and polypeptide synthesis resumes, with simultaneous translocation across the membrane

The signal peptide is cleaved by an enzyme in the receptor protein complex

The rest of the completed polypeptide leaves the ribosome and folds into its final conformation.

Translation

Occurs in the cytoplasm for both eukaryotes and prokaryotes. However, in eukaryotes it is spatially separated from transcription while in prokaryotes it is coupled with it.

Prokaryotes: First tRNA carries formyl methionine; 30s and 50s = 70s ribosome; Has shine dalgarno. Eukaryotes: First tRNA carries methionine; 40s and 60s = 80s ribosome; Binds to 5' end until start codon. Both: Initiator tRNA binds to start codon and large ribosomal subunit joins to form initiation complex.
Polypeptide chains get longer; Ribosomes have 3 binding sites; First tRNA starts at the P site (anticodons of tRNA with codons of mRNA). The A site next to it allows for a tRNA to bind to matching codon forming a peptide bond and then shifting mRNA forward by a codon allowing the empty tRNA to exit through the E site.

Translation comes to an end; Occurs when a stop codon in the mRNA enters the A site. Proteins called release factors recognize stop codons (fit into p site).

Transcription

Termination

RNA Transcript Releases
mRNA is Released

Poly-A Polymerase Adds 100-200 A's to 3' End Using ATP

Cleavage by Ribonuclease at 3' End

Polymerase Detaches from DNA

Elongation

Moves Downstream Unwinding DNA
Elongate RNA Transcript 5' --> 3'

In Wake DNA Reforms Double Helix

Initation

Promoter Includes Nucleotide Sequence TATA Box

Transcription Factor Must Recognize Before Binding of RNA Polymerase II

Additional Transcription Factors Bind with RNA Polymerase to Form Transcription Initation Complex

About 25 Nucleotides Upstream from Transcription Start Point

RNA Polymerase II - pre-mRNA, snRNA, microRNA

snRNA + Spliceosome + Other Proteins

Splice Together Ends of Introns to Form a Ring and Join Exons Together, Introns Form Ring Separate from mRNA

Cut-Out Intron

Spliceosome Components

RNA Polymerase (RNAP)
RNA Polymerases
Binds to Promoter

DNA Unwinds and RNA Synthesis Begins

Start Point (+1)

Can Be In or Directly After Promoter
Read/Template in 3' --> 5'
Downstream (Right = Positive)
Direction of Transcription
Upstream (Left = Negative)

Eukaryotes

Pre-mRNA
Goes Through RNA Processing

RNA Splicing

Alternate Splicing

Splice Together Exons But Can Leave Out 1 or More to Produce Different Proteins During Translation Through Different Exon Sequences

Introns Cut Out/Exons Spliced Together

Exons = Coding Segment

50-250 Adenine Nucleotides Added to 3' End

Poly-A Tail

Polyadenylation Signal

Protein Coding Segments

Start/Stop Codons

5' Cap

Modified Guanine Nucleotide Added to 5' End

Nuclear Envelope

Prokaryotes

Immediately go to Translation Because of No Nucleus

RNA Synthesis

Lagging Strand

DNA Ligase

Seals Gaps Between Fragments

Okazaki Fragments

Leading Strand

Elongated Continuously

Sliding Clamp

Aids DNA Polymerase III

3 Hydrogen Bonds

2 Hydrogen Bonds

Complementary Base Pair in DNA

Complementary Base Pair in RNA

Complementary Base Pair in DNA/RNA

DNA Structure & Replication

Replication Bubble

Origin of Replication
Replication Fork
Separate Double Strand of DNA

Also has DNA Polymerase I in Bacterial Replication

Remove RNA Nucleotides from Primer and Replaces with DNA Nucleotides at 5' End

DNA Polymerase III

Polymerization 5' --> 3'

Bind to RNA Primer

Bonds Nucleotides to Polymer

Removes 2 Phosphate from Nucleotide

2 Inorganic Phosphate Produced

Forms Phosphate Group/Backbone

Primase

Form Okazaki Fragments of Lagging Strand

Synthesize RNA Primers 5' Leading Strand

SSB

Stabilize Unwound Parental Strands

Topoisomerase

Breaks, Swivels, and Rejoins DNA Ahead of Replication Fork Relieving Strain from Unwinding

Helicase

Unwinds and Separates Parental DNA

Double Stranded

Deoxyribose (DNA)/Ribose (RNA) Sugar
Nitrogenous Base

Cytosine

Uracil (RNA)

Thymine (DNA)

1 Nitrogen Ring

Guanine

Adenine

2 Nitrogen Rings

Phosphate Group

Lactic Acid Fermentation


Alcohol Fermentation

Fermentation

Water, H20

Energy released

Complexes I,II, and IV

intermembrane space
ATP Synthesis

Proton motive force

Pi

ADP

Chemiosmosis

Oxaloacetate

Citrate

Isocitrate
Redox reaction: Isocitrate is oxidized; NAD+ is reduced

Redox reaction: After CO2 release, the resulting four- carbon molecule is oxidized (reducing NAD+), then made reactive by addition of CoA

There is an addition of a phosphate to Succinyl CoA which causes GTP to be released and bind with ADP which forms Succinate

Redox reaction: Succinate is oxidized; FAD is reduced

Addition of H20 to Fumarate

Malate

Redox reaction: Malate is oxidized, NAD is reduced

Pyruvate oxidized

NAD+ to form NADH

Acetyl Coenzyme A
Citric Acid Cycle/ Krebb's Cycle

inside mitochondrion

(2) Using energy from this exergonic redox reaction a phosphate group is attached to the oxidized substrate , making a high-energy product

Energy payoff phase

(1) G3P is oxidized by the transfer of electrons to NAD+ , forming NADH

Phosphate group is transferred to ADP (substrate-level phosphorylation) in an exergonic reaction. The carbonyl group of G3P has been oxidized to the carboxyl group (-COO-) of an organic acid (3- phosphoglycerate)
Enzyme relocates remaining phosphate group

Enolase causes a double bond to form in the substrate by extracting a water molecule, yielding phosphoenolpyruvate (PEP) , compound with high potential energy

Phosphate group is transferred from PEP to ADP (second example of substrate- level phosphorylation) forming pyruvate

Energy Investment Phase

Addition of phosphate from ATP to glucose6P using the enzyme of Hexokinase

Glucose 6 phosphate converted to fructose 6-phosphate
Uses enzyme PFK (Phosphofructokinase) to convert fructose6phosphate to fructose1,6 bisPhosphate by transferring a phosphate group from ATP to the opposite end of the sugar, investing a second molecule of ATP

Aldolase cleaves the sugar molecule into two different three-carbon sugars

6 carbon sugar splits into two molecules of 3 carbon each forming DHAP and G3P. Eventually DHAP converts G3P , so at the end we have 2 molecules of G3P from 1 molecule of glucose

Oxidative Phosphorylation

Inner mitochondria membrane

Complexes I,II,III,IV and Q

Glycolysis

Cytoplasm outside mitochondria

Pyruvate Oxidation

In the mitochondrial matrix

Cellular Respiration and Fermentation

Mitochondria Supply ATP

Cell Signaling

Ligand/Signal Molecule

Epinephrine

Smooth Muscle Cell

Cell Relax

Blood Vessel Dilation

Increased Blood Flow to Skeletal Muscle

Beta Receptor

Liver Cell

Glycogen Breakdown

Glucose Release

Blood Glucose Increase

Tyrosine Kinase Receptors

Forms Dimer

6 ATP Activate Tyrosine Kinase Receptors

Phosphorylated Dimer

Active Relay Protein 2

Cellular Response 2

Active Relay Protein 1

Cellular Response 1

Active Relay Molecule

Active Protein Kinase 1

Active Protein Kinase 2

Phosphorylated Protein

Active Protein Enters Nucleus

Binds to Gene as Transcription Factor

mRNA Transcribed

Leaves Nucleus for Ribosome

Ribosome Creates Protein as Response

G Protein Coupled Receptor

Activated GPCR

Binds to G Protein

Activates G Protein

GTP

Hydrolyzed to GDP

Binds to Adenylyl Cyclase

Active Adenylyl Cyclase

Converts ATP to cAMP (Second Messenger)

Activates Protein

Cellular Response

Intracellular Receptors

Accepts Nonpolar Ligands

Membrane Receptors

Accepts Polar Ligands

Photosynthesis

Stroma

Calvin cycle
Regeneration of the CO2 Acceptor (Phase 3)
Reduction (Phase 2)

G3P (Sugar)

Carbon Fixation (Phase 1)

3 phosphoglycerate

Thylakoid Membrane

Light Reaction
Photosystem I

Cyclic

No NADPH

Noncyclic

NADPH:

Electron Transport Chain

Chemosmosis

ATP

Photosystem II

H20

O2

Floating topic

Peptide Bonds

Electrogenic Pumps

Proton Pump (H+)

Generates Voltage (Membrane Potential)

Store Energy for Cellular Work

Membranes

Plasma Membrane

Phospholipid Bilayer
Selective Permeability
Transmembrane Proteins

Alpha Helix

Cytoplasmic C-Terminus

Extracellular N-Termiinus

Attach to CS and ECM

Cell Recognition

Signal

Enzymatic

Bulk Transport

Endocytic

Receptor-Mediated Endocytosis

Pinocytosis

Phagocytosis

Exocytic

Active Transport

Cotransport

Indirect Transport of Other Molecules

Concentration Gradient

Concentration from Low to High

Requires Energy Input

Sodium/Potassium Pump

Ion Channels

Ungated

Gated

Voltage

Ligand

Stretch

Open Potassium Pump

Hyperpolarization

Open Sodium Pump

Depolarization

Passive Transport

Osmosis

Water from Higher to Lower Concentration

Diffusion

Facilitated

Aided by Proteins

Hydrophobic Outside

Hydrophilc Inside

Channel

Carrier

No Energy Input

Hydrophobic Interactions and van der Waals interactions

Primary Structure

Secondary Structure

Beta Pleated Sheets
Tertiary Structure
Hydrogen, Ionic, Dipole-Dipole
Quarternary Structure

Non-Covalent Bonds Between Hydrophilic and Hydrophobic Surface Units

Alpha Helices

Amino Ends Connect to Carboxyl Ends

SH Forms Disulfide Bonds with other SH R Groups (Only Covalent Bond in R Groups)

Ionic Bond

Hydrophilic (Charged)

Cilia helps for prokaryotic cell movement.

Chromosome

Nucleoid

The nucleoid is within the cytoplasm and contains bacterial DNA. The nucleoid regulates the growth, reproduction, and function of prokaryotic cells. Nucleoid is made of DNA, RNA, and proteins. The nucleoid has an irregular shape.

Plasmid

Plasmids are smaller circles of DNA which is transferrable between cells.

Flagellum

Flagella help bacteria move. Flagella may be scattered over the entire surface or concentrated at one or both ends

Cell Wall

The cell wall is outside of the plasma membrane. The cell wall is made of peptidoglycan which is a polymer of modified sugars crossl

Plasma/ Cell Membrane

The plasma membrane is made of phospholipids and proteins. The plasma membrane controls what enters and leaves the cell, provides protection to the cell, and is also the site of many metabolic reactions (example: cellular respiration and photosynthesis).

Capsules or Slime Layers

Glycocalyx: Capsule or Slime Layers. The cell wall is made of many bacteria and is surrounded by a sticky layer made of polysaccharides or proteins. If it's dense and well defined then it's a capsule and if it diffuses is a slime layer. Both sticky outer layers help bacteria to stick (adhere) to a substrate or other bacteria, Sticky outer layers protect against dehydration and some capsules protect bacteria from attacks by the host immune system.

v

Fimbriae are short-hair-like projections on the surface of bacteria that is used to stick to the substrate or to each other.

Function

Fluidity

Viscous

Fluid

Membrane

Permeability

Attachment to cytoskeleton and the ECM
Cell-Cell Recognition
Enzymatic activity
Intercellular Joining
Signal Transduction
Phospolipids
Amphipathic

Phosphate Groups

Fatty Acids

Microtubules

Microtubules are the thickest of the 3 components which contain tubulin polymers. Microtubules are hollow rods made of a protein called tubulin which there are 2 types (alpha and beta). The microtubules consist of a wall with 13 columns of tubulin molecules. Microtubules grow in length by adding tubulin dimers. They are very dynamic. For example, the dimers can be removed to build a microtubule somewhere else in the cell where its needed. The function of microtubules is the maintenance of cell shape, cell motility, chromosome movement in cell division, and organelle movement.

Microfilaments

Microfilaments (Actin filaments, Actin myosis) are the thinnest component of the cytoskeleton. Microfilaments are at the base of the membrane inside the cell which provides a structural role, changes in cell shape, muscle contraction, cytoplasmic streaming (plant cells), cell motility, and cell division (animal cells). Microfilaments help provide support to the plasma membrane and help bear any tension imposed on the membrane from the outside. The structure of microfilaments is two intertwined strands of actin, thin solid rods mode of protein.

Intermediate Filaments

Intermediate Filaments (fibers with diameters middle range) main function is that helps the maintenance of cell shape, anchorage of the nucleus and certain other organelles; formation of the nucleus lamina. Intermediate filaments are the intermediate of the diameter of microtubules and microfilaments. They are very diverse and made of different proteins such as keratin. The structure is made of fibrous proteins coiled into cables, fibrous proteins supercoiled into thicker cables.

Cytoskeleton

Cytoskeletons' relationship to eukaryotic cells:

The cytoskeleton's relationship to eukaryotic cells is that it maintains the cell's shape and it is the anchorage for many organelles.


Cytoskeleton: reinforces cells' shape, functions in cell movement, and components are made up of proteins.

Endoplasmic Reticulum (ER)

Smooth ER relationship to the Endoplasmic Reticulum (ER):

The Smooth ER's relationship to the endoplasmic reticulum is that its part of the ER and helps with lipid synthesis modification.


Rough ER relationship to the Endoplasmic Reticulum (ER):

Rough ER's relationship to the endoplasmic reticulum is that its part of the ER and helps with protein synthesis.


The Endoplasmic Reticulum (ER) accounts for more than half of the nuclear envelope and help the production and storage of proteins.

Rough ER

The Rough ER has bound ribosomes that separate glycoproteins (proteins covalently bonded to carbohydrates), distribute transport vesicles, and is generally considered the "membrane factory" of the cell. The Rough ER produces proteins, produces enzymes, and surrounds a variety of proteins.

Smooth ER

The smooth ER synthesizes lipids, metabolized carbohydrates, detoxifies drugs and poisons, and stores calcium in muscle cells.

Central Vacuoles

Central vacuoles are present in older plant cells which are eukaryotic cells and they include storage breakdown of waste products, hydrolysis of macromolecules, and enlargement of vacuoles.

Contractile vacuoles

Contractile Vacuoles are found in many freshwater protists, and pump excess water out of cells.

Food vacuoles

Food vacuoles are formed when cells engulf food or other particles.

Vacuoles

Vacuoles Relationship to Golgi Apparatus:

Vacuoles' relationship with the Golgi apparatus is that it is derived from the Golgi and gives rise to the organelle.


Vacuoles' Relationship to the Endoplasmic Reticulum:

Vacuoles' Relationship with the ER is that it is derived from it and membrane/ proteins produced by the ER move via transport vessels.

Vacuoles are large vesicles derived from the Endoplasmic Reticulum and the Golgi Apparatus.

Lysosome Phagocytosis

Lysosome Phagocytosis is when enzymes contain active hydrolytic enzymes which fuse with food vacuoles and hydrolytic enzymes digest the food particles.

Lysosome Autophagy

Lysosome Autophagy is when a damaged organelle becomes surrounded by a membrane so it becomes a vesicle. The lysosome enzymes digest the inner membrane and all the materials of the damaged organelle and release them into the cytosol for reuse.

Lysosomes

Lysosomes' relationship to Golgi Apparatus:

Lysosomes' relationship to Golgi Apparatus is that the Golgi Apparatus receives protein enzymes from the ER, which are packed in a vesicle in the Golgi Apparatus, processed, and then pinched off as a lysosome.

Lysosomes are digestive organelles where macromolecules are hydrolyzed, they are membrane-bound organelles packed with enzymes that are used for hydrolysis to break covalent bonds.

Flagellum

Flagellums' Relationship to the plasma membrane:

The Flagellums' relationship to the plasma membrane is that it also extends from the plasma membrane.

The flagellum is a motility structure present in some animal cells, which are eukaryotic cells, composed of a cluster of microtubules with an extension of the plasma membrane.

Cilia

Cilia's relationship to the plasma membrane :

Cilia's relationship to the plasma membrane is that cilia extend from the plasma membrane.

Cilia help with eukaryotic cells' body movement.

Golgi Apparatus

Golgi Apparatus relationship to the Endoplasmic Reticulum:

The Golgi Apparatus' relationship to the Endoplasmic Reticulum is that it receives proteins and lipids (fats) from the ER.


Golgi Apparatus is active in the synthesis, modification, sorting, and secretion of cell products, stores proteins, and make digestive enzyme for lysosomes.

Plasma membrane

Plasma Membrane relationship to Eukaryotic Cells:

The plasma membrane's relationship to eukaryotic cells is that it provides protection.

The plasma membrane encloses the cell.

Mitochondria

Mitonchondria Relationship to the Eukaryotic cell:

The mitochondria' relationship to the eukaryotic cell is the powerhouse of the cell because they generate energy (ATP).

The Mitochondria are the power house of the cell it produces ATP and is the main site of cellular respiration.

Peroxisomes

Peroxisomes' relationship to the Endoplasmic Reticulum:

Peroxisomes' relationship to the Endoplasmic Reticulum is that peroxisomes emerge from the ER.

Peroxisomes detoxify alcohol in the liver and break down fatty acids and amino acids.

Cytoplasm/ Cytosol

Cytoplasm/ Cytosol Relationship to Eukaryotic Cells:

The cytoplasm is present in all eukaryotic cells that carry out complex metabolic reactions and provides support to the organelle's structures.

The cytoplasm is a gelatin-like substance that provides support for organelles to stay in place and it has structural fibers.

Bound Ribosomes

Bound Ribosomes are attached outside of Rough ER or nuclear envelope, making proteins that are either inserted in the membrane or secreted out of the cell.

Free Ribosomes

Free Ribosomes are located in the cytosol, enzymes that catalyze first steps of sugar breakdown.

Ribosomes

Free Ribosome's relationship to Ribosomes:

Free Ribosome's relationship to ribosomes is that its one type of ribosome based on its location in the cytosol.


Bound relationship to Ribosomes:

Bound Ribosome's relationship to ribosomes is that its the second type of ribosome that is based on being in the Rough ER and the nuclear membrane.

Ribosomes are complexes of ribosomal RNA and proteins, the function in cells is to make proteins. Ribosomes have two locations in cells: cytosol or Rough ER and nuclear envelope.

Nucleus




Connections

Nucleus Relationship to Eukaryotic Cells:

The relationship between the nucleus and eukaryotic cells is that all eukaryotic cells contain a nucleus where they store their DNA and control gene expression.


Nucleus Relationship to the nucleolus, nuclear envelope/membrane, chromatin, centrioles, and nuclear lamina (TEM)

The nucleus connects to the nucleolus, nuclear envelope/ membrane, chromatin, centrioles, and nuclear lamina (TEM) because the nucleus has inside all of these organelles.


Nucleolus Relationship to Nucleus:

The relationship between the nucleolus and nucleus is that the nucleolus is located in the nucleus and assembles ribosomes in the nucleus.


Nuclear Envelope/ Membrane Relationship to Nucleus:

The relationship between the nuclear envelope and the nucleus is that it is a structural framework/ support system for the nucleus.


Nuclear Envelope/ Membrane Relationship to Nuclear Lamina (TEM)

The relationship between the nuclear lamina and the nuclear envelope is that the nuclear lamina provides support to the nuclear membrane so it won't collapse and die.


Chromatin Relationship to Nucleus:

The relationship between chromatin and the nucleus is that the DNA of the nucleus helps make up chromatin which helps make chromosomes when cells divide.


Centrioles' Relationship to Nucleus:

The relationship between centrioles and the nucleus is that the centrioles determine the position of the nucleus.


Centriole's Relationship to Chromatin:

The relationship between centrioles and chromatin both help the process of cell division in the nucleus.










The nucleus stores DNA and controls gene expression.

R Group

Orientation

Interactions

Ionic
Hydrophobic
Hydrogen Bonding
Ion Dipole
Disulfide

Amino Acid

Side Chain

R Groups
Basic

Positive Charge

Acidic

Negative Charge

Polar

OH, NH2, SH, CO

Nonpolar

H, CH, CH2, CH3, H2C, H3C

Main Chain

Carboxyl Group
Ionized
Amino Group

Hydrogen Bonds

RNA Bond

DNA Bond

Nucleoside

Link

Ester Linkage

Beta 1-4 Glycosidic Linkage

Alpha 1-4 Glycosidic Linkage

Alpha 1-6 Glycosidic Linkage

Branch Point

Animal

Plant

Beta Glucose

Alpha Glucose

CELLS

Prokaryotic Cells

Biomolecules

Proteins

Receptor
Hormonal
Contractile/Motor
Structural
Transport
Defensive
Enyzmatic

Nucleic Acids

Nucleotides

ar

Ribose Sugar
Base

Purines

Adenine (A)

Guanine (G)

Pyrimidines

Uracil (C)

r

RNA Only (Replace Thymine)

Cytosine (C)

Thymine (T)

Deoxyribose Sugar
Phosphate
Phosphodiester Bond
Ribonucleic Acid (RNA)
Deoxyribonucleic Acid (DNA)
Complementary Base Pairing (Double Strand)
Allows as Base for mRNA Synthesis

mRNA

Gene Expression (Protein Synthesis)

Directs Own Replication

Lipids

Fat Molecule
Triaglycerol

Fatty Acid (Palmitic Acid)

Unsaturated

Cis

Create C Double Bonds (Kink)

Phospholipids

Hydrophobic Tail

Polar/Hydrophilic Head

Same Side H

Trans

Alternating H

Liquid

Saturated

Solid

Hydrophobic (C-H Bonds. Nonpolar)

Glycerol

Carbohydrates

Polysaccharides
Structure

Chitin

Cellulose

Storage

Dextran

Straight

Branched

Glycogen

Starch

Amylopectin