Introductory biology is the study of biomolecules and cellular components that work together to enable the translation of proteins that are the building blocks of living organisms. Through the idea of central dogma and regulation processes that make sure every step of a process is done correctly so that mutation cannot occur, living organisms can produce and live a healthier life.

Central Dogma

Transcription

RNA Polymerase

pulls away two strands of DNA apart from each other and joins together RNA nucleotides complementary to the DNA template strand

Promoter

this allows RNA Pol to attach itself and initiates transcription

Terminator

the sequence that signals the end of transcription

Transcription Unit

the stretch of DNA downstream from the promoter that is transcribed into an RNA molecule

Transcription Factors

a collection of proteins that mediate the binding of RNA pol and initiate transcription

Transcription Initiation Complex

complex of transcription and RNA pol pol 2 bound to the primer

TATA Box

the promoter sequence in DNA in forming the initiation complex at a eukaryotic promoter

RNA Processing

RNA Processing both ends of primary transcript are altered

RNA Splicing

remarkable of stage of RNA processing in the eukaryotic nucleus

Introns

non coding segments of nucleic acid that lie between coding region

DNA Replication

Origin of Replication

Needed in order to begin replication

Replication of DNA begins here

Replication Fork

the "Y' shaped region where parental strands are being unwounded

found on both ends of the replication bubble and open in opposite directions

Single-Stranded Binding Protein

binds to the unpaired strand so they do not pair themselves together

Topoisomerase

an enzyme that helps relieve the tension that was caused breaking, untwisting, and rejoining the DNA strands

Primer

the initial nucleotide chain produced during DNA synthesis that is made up of RNA

Primase

starts a complementary RNA chain with a single RNA nucleotide one at a time using the parental DNA strand as a template

DNA Polymerase

DNA Pol 1

catalyzes the synthesis of new DNA by adding nucleotides to the 3' end of a pre existing chain

DNA Pol 3

adds DNA nucleotides to the RNA primer and continues to add DNA nucleotides complementary to the parental strands

Leading Strand

elongates the new DNA strand in the 5' to 3' end

this only requires one primer for DNA pol 3 to synthesize

Ligase

joins all okazaki fragments into a contiunous DNA strand

Okazaki Fragments

segments that are left by the lagging strand

Exons

the other regions are later translated into amino acids

Spliceosomes

a complex made of of protein and small RNA that remove introns

Translation

tRNA

translates the message in a series of codons along an mRNA molecule

Anticodon

the loop extending from the other end of the L includes

aminoacyl-tRNA synthetases

correct matching up of tRNA and amino acids is carried out by family of related enzymes

ribosomal RNA's

consists of a large subunit and a small subunit, each made up of proteins

Lagging Strand

DNA pol 3 must work in the opposite direction of the fork to keep up with the other complementary strand, this requires multiple primers and it is made discontinuously

Cell Communication

Signaling Molecules travel throughout our body: Local signaling, Long distance signaling, cell to cell communication, physical contact and chemical contact.

Biological Molecules

Proteins

Macromolecules formed by amino acids (polymers)

Amino acids are the monomers

Held together through peptide bonds

Most common molecule used make most of the physical structures in the body

Triglycerides

Macromolecules formed by fatty acids (polymers)

Fatty acids are the monomers

Held together through Ester bonds

Used to make Hormones such as steroids and hormones

carbohydrates

Macromolecules formed of monosaccharides (polymers)

monosaccharides are the monomers

Held together through glycosidic linkage

Used to make both complex and simple sugars which are used for energy

Nucleic acids

macromolecules formed of nucleotides (polymers)

nucleotides are the monomers

Held together through phosphodiester bonds

Used to make genetic material such as DNA and mRNA

Chemical Bonds

Ionic Bonding

Interaction between two activity charged molecules

Example: Bond between K+ and I-

Covalent Bonding

Interaction that result from the sharing of electrons

Example: Bond between Carbon and Oxygen in CO

Hydrogen Bonding

A special kind of covalent interaction that result in the bonding of hydrogen and other more electronegative elements

Highly electronegative elements that can partake in hydrogen bonding: Hydrogen Nitrogen, Oxygen, Fluorine

Example: Bond between Hydrogen and oxygen in H2O

Van Der Waal Interactions

The weakest chemical bond that results from the shifting of electron inside the atom

Example: interactions Between Electrons of Iodide

Water properties

Universal solvent

dissolves more substances than any other solvent

Cohesive behavior

water molecules are attracted to other water molecules

moderate temperature

High Specific heat

High heat of vaporization

Water can moderate temperature because of the two properties: high-specific heat and the high heat of vaporization

Expansion Upon freezing

Denser as a liquid then as a Solid

Denser as a liquid at 3.98°C then when it freezes at 0 degree

Organelles

Ribosomes

complexes made of RNA's and proteins are cellular components

Free Ribosomes

are suspended in the cytosol

Bound Ribosomes

are attached to the outside of the ER

Mitochondria

produces ATP through cellular respiration

Golgi

the transporter of the cell

Plasma Membrane

functions as a selective barrier that allows passage enough oxygen, nutrients, and wastes to service the cell

Selectively permeable membranes

Nucleus

contains most genes of the cell and chromosomes

Nuclear Envelope

encloses the nucleus separating its contents from the cytoplasm

is double membraned

Nuclear Lamina

lines the envelope

a netlike array of protein filaments that maintain shape of the nucleus

Lysosomes

Phagocytosis or "cell eating"

a membrane sac that contains enzymes to digest macromolecules

Endoplasmic Reticulum

Smooth ER

common and important in liver cells

important in synthesis of lipids, oils, and steroids and detox of drugs and poisons

lacks ribosomes

Rough ER

has ribosomes on outer surface

most secretory proteins are knowns as glycoproteins, proteins with carbohydrates that are covalently bonded

it also grows in place by adding membrane proteins and phospholipids to its own membrane

Cell Membrane

Fluid Mosaic: Cholesterol- Give the membrane more fluidity. The cell membrane is both saturated and unsaturated which during temperature change adjusts to make the cell more fluid.

The strucure of the cell membrane gives the membrane a function that allows certain molecules to enter the cell, while others to exits.

Proteins: Cellular transportation

Carbohydrate- cell to cell recognition.

Lipids: Phospholipid- hydrophobic tails and hydrophilic head makings the membrane fluid.

Trans-membrane protein, channel proteins, ion gated, and carrier proteins: found on the cell membrane to allow the transport of certain molecules into and out of the cell

G Protein Receptor and Tyrosine Kinase Receptor

Signaling Molecules bind to the receptors and activates

G Protein: Binds to the G protein receptor and change shape, removing GDP and adding GTP which makes the protein active

The active G protein then goes and activates a near by enzyme. Example: Adenylyl Cyclase

Adenylyl Cyclase convertes ATP into cAMP which is a secondary messenger.

cAMP then activates Protein Kinase A which through phosphorylation activates another Kinases and cascade until the last protein acceptor. PHOSPHORYLATION CASCADE

The last protein goes into the nucleolus and and activates transcription factors to start the transcription complex and let RNA Poly make protein OR gene to be expressed

Gene Regulation

Eukaryotic

Eukaryotic Cells have gene regulation at two control elements: Distal control element and Proximal control element, where there are DNA sequence called enhancer where activators or repressors can bind to to start or inhibit the transcription initiation complex.

Prokaryotic

Prokaryotic cells have gene regulation sequences called operon where it contains operator and promoter for activators or repressor to bind to to allow RNA Poly to start transcription.

Last protein acceptor then sends the signal to organelles in the cytoplasm

When two signaling molecules bind to the Tyrosine Kinase Receptor the tyrosines dimerize and through phosphorylation 6 ATP is converted into 6 ADP and 6 P, the 6 phophasete groups bind to the 6 tyrosines activating the tyrosin Kinase Receptor

Ion Gated Channels

These channels allow for the entering and existing of ions into and out of the cell. Example: K+/N+ Pump

The cell has a negative concentration compare to the outside of the cell. There is more K+ inside the cell and more N+ outside of the cell. The cell take in 2 K+ and 3 N+ out to stabliize the cell.

Nerve cells send out neurotransmitters when the membrane potential reaches the highest capacity called action potential, neurotransmitters then act like signaling molecules passing through the synaptic cliff and binding to gated ion channels and opening them so that the neuron can respond.

Experiments

Miller Urey

Set up a closed experiment to mimic conditions of primidal atmosphere

Found: Formaldehyde and Hydrogen Cyanide and other complex molecules such as amino acids and long chains of carbons and hydrogen also known as hydrocarbons

Hershey and Chase

Phages were grown with radioactive Sulfur and protein was dyed pink

Phage was found in liquid rather then pellet which proved protein was not the genetic material

Phages were grown with radioactive phosphorus and DNA was dyed blue

Phages was found in pellet rather then liquid which proved that DNA was the genetic material

Griffith

studied two different strains of the bacterium Streptococcus pneumoniae

The S (smooth) Strain

Pathogenic because Cells have a smooth outer capsule

Heat Killed S Cells (non path control) mouse lived

Living S Cells (Pathogenic Control) killed mouse

Mixture of R cells and heat killed S Cells killed the mouse

The R had been transformed into pathogenic S bacteria

The R (Rough Strain)

Non Pathogenic because cells do not have a capsule

Living R Cells (Non Path Control) mouse lived

Meselson and Stahl

Conservative Model

Two parental strands reassociate after acting as templates for new strands, which restores the parental double helix

Semiconservative Model

Two strands of parental molecule separate and each function as a template for new strand.

Proved to be the accurate model for DNA

Dispersive Model

Each strand of daughter and parent molecule has a mix of old and new DNA