Anabolic Metabolism and Genetics Overview

polymer

chain made up of repairing, similar units; made of monomers

monomer

individual units, single part of chain

starches vs. fats - density

fats are much denser energy storage than starch

starches vs. fats - utilization

starches are easier to utilize because they are rapidly mobilized

bacteria preference for energy storage

Bacteria would prefer starches when they need medium-term energy storage, rapid energy utilization (fast mobilizing). Fats are almost never used since it's denser and slow mobilizing.

structural components of starch

key component in cell walls: peptidoglycan, cellulose, chitin; also modifies proteins and fats

structural components of fats

key components in cell membrane: phospholipids, fatty acid chains; also used for modification: lipoproteins, lipopolysaccharides

central dogma of biology

the flow of genetic information from DNA → RNA → proteins

DNA

acts as the blueprint for all necessary information of an organism; permanent

RNA

temporary photocopies of information that the cell needs to do right now; only for what we need to do right now

proteins

machines built from the instructions of the RNA; made by 'reading' the RNA

building blocks of DNA

nucleotides composed of: deoxyribose sugar, phosphate group, nitrogenous bases

4 bases in DNA

adenine (A), guanine (G), thymine (T), cytosine (C)

rules of base pairing in DNA

adenine pairs with thymine (A-T); guanine pairs with cytosine (G-C)

semi-conservative replication

the end product of DNA replication will be 50% new and 50% original

DNA replication process

take a DNA molecule → break hydrogen bonds between base pairs → either strand can be template → template strand is used to make complementary strands → double DNA

prokaryotic origins of replication

have one origin of replication on circular chromosome

eukaryotic origins of replication

have many origins of replication spread out across their linear chromosome

building blocks of RNA

ribose sugar, phosphate group, nitrogenous bases

4 bases in RNA

adenine (A), guanine (G), uracil (U), cytosine (C)

difference in RNA base from DNA

uracil instead of thymine

transcription process

start with DNA molecule → melt hydrogen bonds → pick one strand and make complementary strand, RNA transcript → after complementary strand is made, that RNA transcript floats off → DNA closes back up, remains unchanged

difference between transcription and DNA replication

transcription creates RNA from DNA, while DNA replication creates a duplicate DNA molecule.

Polymerase

An enzyme that synthesizes RNA from a DNA template.

Gene

Segments of DNA that are transcribed.

Amino Acid

A molecule consisting of an amino group, central carbon, and carboxyl group.

Polypeptide

A chain of amino acids joined together by peptide bonds.

Side Groups

Chemical groups attached to amino acids that can be hydrophobic or hydrophilic, small or bulky, acidic or basic.

Translation

The process of building a protein from messenger RNA using ribosomes.

Codon

A sequence of three nucleotides that form a unit of genetic code.

Start Codon

AUG, the codon that signals the start of translation.

Stop Codon

A codon that signals the messenger RNA to stop translating.

Central Dogma

The flow of genetic information from DNA to RNA to protein.

Substitution Mutation

A mutation that changes one base in the DNA sequence.

Insertion/Deletion Mutation

A mutation that adds or subtracts one or more bases from the DNA sequence.

Silent Mutation

A mutation where the base is changed, but there is no amino acid change.

Nonsense Mutation

A mutation that changes an amino acid to a stop codon.

Missense Mutation

A mutation that causes a change in the amino acid in the final sequence.

Frameshift Mutation

A mutation that affects downstream amino acids by shifting the reading frame.

In-Frame Deletion

A deletion mutation that removes an amino acid but maintains the reading frame.

Mutation Rate of HIV

HIV has a high mutation rate, leading to high error rates and ease of developing drug resistance.

Mutagen

Anything that increases the rate of mutation.

Carcinogen

Anything that increases the rate at which an individual gets cancer.

Ames Test

A test that determines the mutagenic potential of a substance, often using rat liver enzymes.

Ames test

A test that tells you if a chemical is a mutagen in bacteria.

Mutation rate

The frequency at which spontaneous mutations occur in a given population of organisms.

Reversion mutation

A mutation that restores function to a gene.

Vertical gene transfer

The movement of genetic information from parent to its offspring.

Horizontal gene transfer

The transfer of genes between unrelated organisms; donor transfers DNA to a recipient cell, and it becomes permanent.

Transformation

When a bacteria scoops up DNA from its environment and incorporates it into its own genetic material.

Competent

The ability of a bacteria to accept genetic material from its environment.

Conjugation

A process where a donor cell carries a specialized plasmid (F factor) and transfers it to a recipient cell.

Donor cell

The cell that carries the F factor in conjugation.

Recipient cell

The cell that lacks the F factor in conjugation.

Transduction

When a bacteriophage accidentally picks up a piece of bacterial DNA and transfers it into a new host.

Bacteriophage

Viruses that infect only bacteria.

Plasmid

Small pieces of DNA that contain extra genes not necessary for survival.

R factor

Plasmids that carry genes that can confer resistance to antibiotics.

RTF factor

Genes that carry resistance to antibiotics and conjugation genes, allowing rapid horizontal growth.

Competency in bacteria

Only a few bacteria are naturally competent, but almost all can be made competent.

Griffith's experiment

An experiment where heat-killed strain A leaked DNA that caused strain B to transform.

Chemical mutagen

A substance that causes mutations in DNA.

F factor

A specialized plasmid that allows for conjugation.

Spontaneous mutation rate calculation

The process of determining the mutation rate by comparing the number of colonies before and after adding a suspected mutagen.

Ames test positive result

Indicates that some bacteria had a reversion mutation and can now synthesize histidine.