Bio Test 5

Front 1

What kind of bonds between nitrogenous bases in DNA?

Back 1

Hydrogen

Front 2

What does DNA contain?

Back 2

Instructions for making proteins

Front 3

DNA replication

Back 3

Parent strands unwind and two new daughter strands are built

Front 4

Base pairing rules

Back 4

A with T, C with G

Front 5

Helicase

Back 5

Unzips DNA molecule

Front 6

Single-stranded binding proteins

Back 6

Keeps 2 parent strands apart after helicase unzips them

Front 7

Topoisomerase

Back 7

Unwinds double helix, prevents twisting ahead of replication fork

Front 8

Primase

Back 8

RNA primers, need this to start process

Front 9

DNA Polymerase (III & I)

Back 9

III: replaces RNA nucleotides w/ DNA nucleotides to the 3' end

I: cleans up RNA primer

Front 10

Leading Strand

Back 10

moves toward replication fork, only one primer

Front 11

Lagging Strand

Back 11

away from fork, multiple primers

Front 12

Leading Strand Steps

Back 12

1 set of RNA primase makes primer, polymerase III adds DNA nucleotides, polymerase I cleans up RNA primer

Front 13

Lagging Strand Steps

Back 13

Multiple RNA primases make primer, making gaps between primases. Okazaki fragments fill in gaps by polymerase III, DNA ligase acts as glue for okazaki fragments, Polymerase I cleans up RNA primer.

Front 14

Nucleotides excision repair

Back 14

Nuclease cuts out damaged DNA

Front 15

Mutations

Back 15

Change in DNA sequence

Front 16

Telomeres

Back 16

DNA sequencing at the end of eukaryotic chromosomes

Front 17

Telomerase

Back 17

Enzyme that lengthens the telomeres in gamete making cells so that DNA is not missing

Front 18

Chromatin

Back 18

Complex of DNA and protein; found in the nucleus of eukaryotic cells

Front 19

Euchromatin

Back 19

Loosely packed chromatin, actively transcribed genes are present.

Front 20

Heterochromatin

Back 20

Telomere and centromere regions. Tightly packed chromatin, no transcription.

Front 21

Histones

Back 21

Proteins around which DNA is wrapped thus condensing the chromosome structure

Front 22

Mismatch repair

Back 22

The cellular process that uses special enzymes to fix incorrectly paired nucleotides

Front 23

Nucleosome

Back 23

Bead like structure consisting of DNA wrapped around histone proteins

Front 24

What phase is DNA replicated in the cell cycle?

Back 24

S phase

Front 25

Protein Synthesis occurs in how many stages?

Back 25

2: Transcription and Translation

Front 26

Transcription

Back 26

Making of mRNA from DNA sequences

Front 27

Translation

Back 27

Creating polypeptide chains with mRNA instruction, occurs in ribosome

Front 28

Codon

Back 28

Codes for specific amino acid, groups of 3

Front 29

What are the three stages of transcription?

Back 29

Initiation, Elongation, Termination

Front 30

Initiation in Transcription

Back 30

Promoter region: the site where RNA polymerase attaches, RNA polymerase: adds RNA nucleotides, Transcription factors: bind RNA polymerase to promoter region

Front 31

Elongation in Transcription

Back 31

RNA chain is made

Front 32

Before translation

Back 32

eukaryotes must convert pre-mRNA to mRNA, 2 protective structures in pre-mRNA: Poly a tail (3’ end) & Cap (5’ end)

Front 33

Initiation in Translation

Back 33

Small ribosomes attach to mRNA

Front 34

Anticodon

Back 34

Identical to template strand

Front 35

Codon

Back 35

Identical to non template strand

Front 36

Elongation in translation

Back 36

P site: does initial accepting of tRNA, A site: holds tRNA/accepts new codons

Front 37

Termination in translation

Back 37

E site: tRNA exits

Front 38

tRNA

Back 38

transfer RNA, specific amino acid on one end and anticodon on other end

Front 39

RNA splicing

Back 39

removing introns, expression exons

Front 40

mRNA

Back 40

messenger RNA, specifies structure of protein

Front 41

Acetylation of histones

Back 41

Adding an acetyl group (CHCO3), makes chromatin less compact and transcription can occur.

Front 42

Deacetylation of histones

Back 42

Removing an acetyl group (CHCO3), makes chromatin more compact and transcription is prevented.

Front 43

DNA methylation

Back 43

The presence of methyl groups on DNA bases (usually cytosine). Typicallyprevents transcription.

Front 44

Histone charge

Back 44

Positive tails attracted to negative DNA, reducing transcription

Front 45

What happens if transcription does not occur?

Back 45

Proteins will not be made/expressed