Biochem Lecture 8

central dogma

DNA to RNA to protein

gene expression

the turning on or activation of a gene

ribonucleic acids

RNA

deoxyribonucleic acids

DNA

nucleoside

base and a sugar

nucleotide

base, sugar, and a phosphate

adenosine 5’-triphosphate (ATP)

common currency in which energy gained from food is converted and stored

nucleic acids

chain of nucleotides

structure of DNA

• archival storage

• deoxyribose

• ATCG

• double stranded

structure of RNA

• working copy

• ribose

• AUCG

• single stranded

double helix

two polynucleotide strands are coiled around each other

components of stability

base-pairing and pi-stacking

A + T

2 hydrogen bonds

G + C

3 hydrogen bonds

denaturation

the separation of two complementary strands

annealing

reformation of hydrogen bond between complementary strands

heat denaturation

melting

Tm

higher when G-C% is higher

histones

proteins that DNA is coiled around, have basic amino acids Lys and Arg

nucleosomes

eight histones wrapped around the DNA helix

chromatin

condensed nucleosomes

What forms the superstructure of chromosomes?

chromatin fibers organized into loops

tertiary structure in DNA

the supercoiling of the DNA molecule

How many genes does the human genome have?

25000

The strands in the double helix ________-_

have their 3’-5’ direction opposed

replication fork

where replication begins at a point in the DNA

replication of DNA

1. opening of the superstructure of the chromosomes

2. relaxation of higher-order structures of DNA

3. unwinding the DNA double helix

4. DNA polymerase

5. primers/RNA primers

6. ligase

acetylation-deacetylation

removes positive charge

topoisomerase

relax the supercoiling in DNA strands

helicase

cause the separation of the double helix

DNA polymerase

enables complementary base pairing joined by hydrogen bonds

Which direction is the leading strand synthesized?

5’ to 3’ direction

primer

initiate the primase-catalyzed synthesis of both daughter strands

ligase

joins okazaki fragments

replication

duplication of DNA, requires RNA

transcription

process of formation of RNA on a DNA template

translation

protein synthesis

Which type of RNA carries amino acids for the process of translation

tRNA

Where does majority of protein synthesis occur?

cytoplasm

What is the template for protein synthesis?

mRNA strand

DNA-binding domain

part of a transcription factor that binds to the DNA

types of DNA-binding domains

• helix-turn-helix

• zinc fingers

• basic region leucine zipper

transcription-activation domain

interacts with other proteins and complexes rather than with DNA directly

process of transcription

DNA is used as a template to create mRNA and assembled the complementary RNA strand

process of translation

tRNA binds specific amino acids to make anticodon then the protein chain