Chapter 7.5 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

TRANSCRIPTION

A

copies the information encoded in a DNA base sequence into complimentary language of mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

TRANSLATION

A

Builds the protein. The actual construction of proteins.
Using the instructions from mRNA to build a protein by joining amino acid into a polypeptide sequence

It is the translation of the mRNA sequence into a sequence of amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

GENETIC CODE

A

is the set of rules by which a cell uses the nucleotides in mRNA to assemble amino acids into a protein. It also contains direction for starting and stopping translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

A CODON

A

is a group of 3 mRNA bases that corresponds to one amino acid or to a “stop” signal. Nearly all species use the same mRNA codons to specify the same protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How many amino acids in life

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is typically the first codon of mRNA

A

AUG- the start codon ( methionine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

the 3 stop codons in mRNA

A

UGA, UAA, UAG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What participants are needed in translation

A
  1. mRNA
  2. tRNA
  3. Ribosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

mRNA

A

product of transcription carries the genetic information that encodes a protein with each 3 base codon specifying a amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

tRNA

A

This bilingual molecule binds to a mRNA codon and to an amino acid.It contains an ANTICODON that is complimentary to one mRNA CODON

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

ANTICODON

A

is a 3 base loop that is complimentary to one mRNA codon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is on the opposite end of of the anticodon on a tRNA

A

it forms a covalent bond to the amino acid corresponding to that codon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The anticodon for methionine

A

methionine codon on mRNA is AUG : on the transfer RNA the anti codon would be UAC with methionine attached to the opposite end.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

RIBOSOME

A

. built of rRNA and proteins
. Anchors mRNA during translation
.They consist of a large and small subunit at join at the initiation of protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where are ribosomes in the cell

A
  1. free in the cytoplasm or

2. attached to the rough endoplasmic reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The 3 steps of TRANSLATION

A
  1. Initiation
  2. Elongation
  3. Termination
17
Q

INITIATION

A
  1. The leader sequence at the 5’ end of the mRNA molecules bonds with a small ribosomal unit.
  2. The first codon is usually AUG which attracts a tRNA that carries the amino acid methionine.
    The methionine signals the start of the the polypeptide chain

3, A large subunit of ribosome attaches to the small subunit to complete initiation

18
Q

ELONGATION

A

1.a tRNA molecule carrying the second amino acid , then binds ( a hydrogen bond) to the second codon on the mRNA
molecule.

  1. The first and second amino cid align forming a covalent bond= a peptide bond
  2. With the peptide bond in place the ribosome releases the first tRNA, which will pick up another methionine and be used again.
  3. The ribosome moves down my one codon. The steps are repeated.
19
Q

ELONGATION FACTORS

A

are proteins that help the polypeptide to grow one amino acid at a time

20
Q

TERMINATION

A

Elongation halts at a stop codon ( UGA< UAG, or UAA). No tRNA molecule corresponds to these codons.

  1. Instead proteins called RELEASE FACTORS bind to the stop codon prompting the release of the last tRNA from the ribosome.
  2. The ribosomal sub units separate from each other
  3. The polypeptide is released
21
Q

The stop codons

A

UGA, UAG, UAA

22
Q

. What happens in each stage of translation?

A

The steps of translation are initiation (ribosomal subunit binds to initiator codon), elongation of the polypeptide, and termination (release of the last tRNA from the ribosome, signified by a stop codon).

23
Q

Where in the cell does translation occur

A

Translation occurs at ribosomes, which are either free in the cytoplasm or attached to the rough ER.

24
Q

How are polypeptides modified after translation?

A

Polypeptides have to be folded into proteins; sometimes amino acids are cut out of the chain, and sometimes multiple polypeptides join together.

25
Q

What bonds are formed with the anticodon and the codon on mRNA

A

HYDROGEN BOND

26
Q

what bond are formed between the amino acids on the growing polypeptide chain

A

COVALENT PEPTIDE BONDS

27
Q

What stabilizes proteins

A

CHAPERONE proteins