Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOLOGY > 4A dna rna protein synthesis > Flashcards

4A dna rna protein synthesis Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Describe DNA in eukaryotic cells

A

carry DNA as chromosomes- threadlike- made up of one long molecule of DNA found in nucleus

  • the DNA molecule is rlly long it has to be wound up to fit in nucleus
  • wound around proteins called histones
  • DNA and histones coiled up v tightly to make compact chromosome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why are histones helpful in DNA

A

help support the DNA

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

mitochondria and chloroplasts in eukaryotic cells have there own DNA - describe it

A

circular and shorter than DNA in nucleus and not associated to histones
similar to prokaryotic DNA

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

describe dna molecules in prokaryotic cells

A
  • also carry DNA as chromosomes but the DNA is shorter and circular
  • not wound around histones-condenses to fit in cell via supercoiling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is a gene

A

Sequence of DNA bases that code for either a polypeptide or functional RNA

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

What do the sequence of amino acids in a polypeptide form

A

The primary structure of a protein

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

What determines the order of amino acids in a particular polypeptide

A

Different polypeptides have different numbers and orders of amino acids -the order of bases in a gene determines the order of amino acids

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

What is each amino acid is coded by

A

A sequence of three bases in a gene called a triplet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a triplet

A

A sequence of three bases in a gene

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

What is functional RNA

A

RNA MOLECULES OTHER THAN MRNA WHICH PERFORM SPECIAL TASKS DURING PROTEIN SYNTHESIS LIKE T RNA AND RIBOSOMAL RNA

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

What is a Genome

A

The complete set of genes in the cell

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

What is a cells proteome

A

The full range of proteins that the cells able to produce

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

What are introns

A

In eukaryotic DNA genes that code for polypeptides contain sections that don’t code for amino acids these are introns

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

what are exons

A

sections in gene that do code for amino acids

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

When are Introns removed

A

During protein synthesis

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

do prokaryotic cells have introns

A

no

17
Q

What are non-coding repeats

A

DNA sequences that repeat over these don’t code for Amino acids

18
Q

What is another form of gene can exist in

A

alleles

19
Q

How can alleles code for different versions of the same polypeptide

A

The order of bases in each allele is different

20
Q

What is a homologous pair

A

Pairs of matching chromosomes

21
Q

what do chromosomes in a homologous pair have

A

same genes, same size but can have different alleles

22
Q

summary of genetic code

A

each triplet of bases coding for a particular amino acids known as a codon. amino acids are then joined together by peptide bonds and form a polypeptide chain. Therefore a gene is a sequence of bases on a DNA molecule coding for a sequence of amino acids in a polypeptide chain.

23
Q

describe first stage of protein synthesis - transcription

A

During- mRNA copy of gene made from DNA

1- starts when RNA polymerase attaches to DNA double helix at begin of gene

2- H bonds between the complementary bases break via DNA he w/ RNA po so DNA uncoils, separating two strands exposing some bases

3-one of the strands then used as template to make mrna copy

4-RNA po lines up free RNA nucleotides by exposed bases and joins them, complementary base pairing causes mRNA molecule to be formed -being a copy of DNA template

5-H bonds reform between uncoiled DNA strands once rna po has passed- the strands then coil back to double helix

6-when rna po reaches stop signal it detaches-stopping making mRNA

7-mrna moves out of nucleus via nuclear pore & attaches to ribosome in cytoplasm

24
Q

what is mRNA

A

Made during transcription
carries genetic code from DNA to ribosome is then used to make protein during translation
single polynucleotide strand

25
Q

What is tRNA

A

-Involved in translation
- carries amino acids , used to make proteins, to ribosomes
-single polynucleotide strands folded into clover shape
H bonds between specific base pairs hold in this shape
- tRNA has sequence of three bases at one end called anti codon and have Amino acid binding site at other end

26
Q

MRNA strands containing introns & exons is called

A

pre mRNA

27
Q

what is splicing

A

when introns are removed from pre mrna and exons are joined together to make mRNA
takes place in nucleus -then strand leaves nucleus for translation

28
Q

describe second stage of protein synthesis- translation

A

During - amino acids joined together t make polypeptide chain following codons carried by mRNA

1-mrna attaches to ribosome, trna carries amino acids to it (ATP provides energy needed for bond from AA to trna)

2-tRNA attaches itself to mRNA by complementary base pairing – two molecules attach to mRNA at a time via anticodon to codon.

3- amino acids attached to two tRNA molecules join by a peptide bond then tRNA molecules detach themselves from the amino acids, leaving them behind.

4-This process is repeated , leading to the formation of a polypeptide chain until a stop codon is reached on mRNA and ends the process of protein synthesis.

29
Q

why is the genetic code described as degenerate

A

as a single amino acid may be coded for by more than one codon

30
Q

Why are genetic code described as degenerate.

A

degenerate meaning that more than one triplet codes for the same amino acid,
this reduces the number of mutations which are mistakes in the base sequence such as base deletion, insertion or substitution

31
Q

how many bases are exposed at a time during transcription

A

12 bases being exposed at a time to reduce the chance of damage to the DNA.

32
Q

why is the genetic code described as universal

A

The same specific base triplet code for the same amino acids in all living things

BIOLOGY (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions