Ch. 10

Question 1

What distinguishes the 20 types of amino acids in proteins?

Answer 1

R group (side chain)

Question 2

Polypeptides

Answer 2

one or more long chains of amino acids

Question 3

Conformation

Answer 3

protein’s 3D shape

Question 4

Transcription

Answer 4

synthesizes RNA molecule

Question 5

Translation

Answer 5

uses the info in RNA to make protein by aligning and joining specified amino acids

Question 6

Central Dogma

Answer 6

(nucleus)replication- DNA - transcription- RNA - (cytoplasm) translation - protein

Question 7

RNA polymerase

Answer 7

builds an RNA molecule (during transcription)

Question 8

Messenger RNA (mRNA)

Answer 8

least abundant; carries info for a particular protein

Question 9

codon

Answer 9

3 mRNA bases in a row = specified amino acid

Question 10

Ribosomal RNA (rRNA)

Answer 10

most abundant; associates with certain proteins to form ribosomes, forms part of the enzyme that drives translation

Ribozymes: catalyst align ribosome and mRNA

Question 11

Transfer RNA (tRNA)

Answer 11

transports specific amino acids to the ribosome for protein synthesis (translation); links amino acid to anticodon

clover or L shaped

Question 12

Steps of Transcription

Answer 12

1. Initiation
2. Elongation
3. Termination

Question 13

Transcription Initiation

Answer 13

transcription factors and RNA polymerase attracted to a promoter, then RNA polymerase binds start of sequence

Question 14

Transcription Elongation

Answer 14

enzymes unwind DNA double helix 5’-3’
free RNA nucleotides bond w/ exposed complementary bases and RNA polymerase adds RNA nucleotides

Question 15

Transcription Termination

Answer 15

terminator sequence in dna indicates end

Question 16

TBP

Answer 16

general transcription factor that is essential for all transcription of all genes

Question 17

mRNA Processing (maturation of message)

Answer 17

DNA template strand (3’-5’) - transcription - pre- mRNA - modification - 5’ mRNA cap & 3’ poly A tail - splicing - mature mRNA cap - transport out of nucleus into cytoplasm for translation

Question 18

mRNA translation

Answer 18

assembles a protein from mRNA sequence, uses codon (group of 3 bases) to turn into amino acid sequence (polypeptide)

Question 19

Codon

Answer 19

three successive mRNA bases

64 codons

Question 20

Reading frame

Answer 20

altering DNA sequence by 1 or 2 bases produces a different amino acid sequence due to disruption, causes frame-shift mutation

Question 21

Translation

Answer 21

needs mRNA, tRNA’s w/ amino acids, ribosomes, energy molecules (ATP, GTP) and protein factors

the closer the end of the gene, the longer the polypeptide

Question 22

Translation Steps

Answer 22

1. Initiation
2. Elongation
3. Termination

Question 23

Protein Primary Structure

Answer 23

sequence of amino acids in a polypeptide chain

Question 24

Protein Secondary Structure

Answer 24

loops, coils, sheets, or other shapes form by h-bonds between neighboring carboxyl and amino groups

Question 25

Protein Tertiary Structure

Answer 25

3D forms shaped by bonds between R groups, interaction btwn R groups and water

Question 26

Protein Quaternary Structure

Answer 26

protein complexes formed by bonds btwn separate polypeptides

Question 27

Protein Folding

Answer 27

fold after the amino acid chain winds away from the ribosome; helped by chaperone proteins or if damaged go to proteasome

Question 28

This substance contains the genetic information for the production of a protein from a structural gene

Answer 28

mRNA

Question 29

This is the process of producing an RNA copy of a gene

Answer 29

Transcription

Question 30

This is the process of synthesizing a specific sequence of amino acids on a ribosome.

Answer 30

Translation

Question 31

This substance in the nucleus of cell constitutes the cell’s genome

Answer 31

DNA

Question 32

This is a sequence of amino acids that correspond to the genetic information in a structural gene.

Answer 32

Polypeptide

Question 33

DNA

Answer 33

contains thymine, double stranded, contains deoxyribose

Question 34

RNA

Answer 34

contains ribose, single stranded, contains uracil

Question 35

You are studying the levels of proteins in different tissue types in samples from mice. The levels of some proteins are rather uniform among tissue types. In contrast, you are surprised to find that a protein called class III β-tubulin is present only in brain tissue from the mouse and is undetectable in other tissues.

What is the most likely explanation for this finding?`

Answer 35

The difference is most likely due to the action of transcription factors; All cells in an organism have the same genes. The difference in gene expression between different cells is largely due to the action of transcription factors. Transcription factors respond to signals from outside the cell that control what genes are expressed in what cells and when.

Question 36

Transcription factors function in the expression of genes by

Answer 36

turning transcription of specific genes on or off.