Lecture 0 - Prerequisite

Question 1

Two roles of genetic material

Answer 1

1. Contain complex information
2. Replicate faithfully

Question 2

Central dogma

Answer 2

DNA to DNA (replication)
DNA to RNA (transcription)
RNA to protein (translation)

Question 3

Central dogma for viruses

Answer 3

DNA to RNA (transcription)
RNA to DNA (reverse transcription)
RNA to RNA (rna replication)
RNA to proten (translation)

Question 4

Components of a nucleic acid

Answer 4

5-carbon sugar, phosphate group, nitrogenous base

Question 5

Purines

Answer 5

adenine and guanine

Question 6

Pyrimidines

Answer 6

cytosine, thymine, uracil

Question 7

Polynucleotide connections

Answer 7

Has polarity - nucleotides are connected by the 3rd and 5th carbon atoms on the sugar, results in the strand having a 3’ end and a 5’ end

Question 8

DNA base pairing

Answer 8

AT - 2 hydrogen bonds
CG - 3 hydrogen bonds

Question 9

DNA replication phases

Answer 9

G0 - rest
G1 - cell size increases
S - dna replication
G2 - cell size increases

Question 10

Theta replication

Answer 10

dna replication that is common in bacteria (circular dna), a loop forms that causes the dna to unwind, forming a structure that resembles theta, results in 2 circular dna products

Question 11

Rolling circle replication

Answer 11

common in plasmids and bacteriophage

Question 12

Linear replication

Answer 12

common in eukaryotes

Question 13

Initiation of linear replication

Answer 13

Origin recognition complex (6 proteins) begins dna unwinding, multiple origins speed up replication

Question 14

Enzymes involved in elongation step of linear replication

Answer 14

Helicase - breaks down hydrogen bonds between base pairs and continues unwinding of dna

Single strand binding proteins - bind to single strand to prevent a secondary structure

DNA gyrase - relaxes torque of upstream dna

Question 15

DNA is synthesized from ___, and is read from ___

Answer 15

Synthesized 5’ to 3’, read from 3’ to 5’

Question 16

Alternative splicing

Answer 16

RNA transcripts can be spliced in different ways which can yield different proteins from the same gene

Intron is removed, exon is kept

Question 17

How many functional side chains are there for amino acids

Answer 17

Around 23, 20 standard

Question 18

Length of Okazaki fragments

Answer 18

Around 200 base pairs

Question 19

How often do mammalian polymerases make errors

Answer 19

Every 100 million base pairs

Question 20

How many errors does proofreading correct?

Answer 20

99%

Question 21

How many genes are in the human genome?

Answer 21

20,000-25,000