Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

4U BIO > 6.1/6.2/6.3 > Flashcards

6.1/6.2/6.3 Flashcards

1
Q

One-Gene/One-Polypeptide Hypothesis

A

A proposal that one gene codes for one polypeptide (or protein)

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

Messenger RNA (mRNA)

A

RNA that contains the genetic information of a gene and carries it to the protein synthesis machinery; provides the information that determines the amino acid sequence of a protein.

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

How is mRNA synthesized?

A

It is synthesized from the DNA of genes.

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

The mRNA base sequence would be ____________ to the gene DNA sequence.

A

Complementary

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

Genetic Code

A

A set of rules for determining how genetic information in the form of a nucleotide sequence is converted to an amino acid sequence of a protein; a code specifying the relationship between a nucleotide codon and an amino acid.

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

Triplet Hypothesis

A

A proposal that the genetic code is read three nucleotide bases at a time.

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

Codon

A

A combination of three nucleotides.

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

How is the genetic code always interpreted?

A

In terms of the mRNA codon rather than nucleotide sequence of the DNA.

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

Three Important Characteristics of the Genetic Code

A

1) It is redundant.
2) It is continuous.
3) It is nearly universal.

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

The Genetic Code is Redundant

A
  • More than one codon can code for the same amino acid.

- Three codons don’t code for any amino acid. (Serve as ‘stop’ signals that end protein synthesis)

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

The Genetic Code is Continuous

A

-reads as a series of three-letter codes without spaces, punctuation of overlap

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

The Genetic Code is Nearly Universal

A

-almost all organisms build proteins with the same genetic code

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

Gene Expression

A

The transfer of genetic information from DNA to RNA to protein.

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

Central Dogma

A

The theory that genetic information flows from DNA to RNA to protein.

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

Two Steps in Gene Expression

A
  • Transcription

- Translation

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

Transcription

A

The synthesis of RNA from a DNA template.

-mRNA is synthesized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Translation

A

The synthesis of protein from an mRNA template.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is DNA often described as?

A

The blueprint of a cell, which stores information needed for survival and reproduction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where is RNA synthesized?

A

Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Messenger RNA (mRNA)

A
  • the RNA strand that is synthesized in the nucleus and carries the template for translation to the cytoplasm
  • nucleus –> cytoplasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Transfer RNA (tRNA)

A
  • transport amino acids to ribosomes
  • positions each amino acid at correct place on polypeptide chain
  • cytoplasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Ribosomal RNA (rRNA)

A
  • site of polypeptide synthesis (not involved in coding)

- ribosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the main objective of transcription?

A

To accurately produce a copy of a small section of genomic DNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Three Stages of Transcription

A

Initiation, Elongation, Termination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
For each gene, how many strands of double-stranded DNA molecules are transcribed?
Only One
26
Antisense Strand
- the strand of DNA that is transcribed | - 'non-coding strand'
27
Sense Strand
- the strand of DNA that is not transcribed | - 'coding' strand
28
RNA Polymerase
The main enzyme that catalyzes the formation of RNA from a DNA template.
29
At what point does transcription begin?
- When RNA polymerase binds tightly to a promoter region on the DNA - DNA is unwound and opens a section of the double helix
30
Promoter Region
A sequence of nucleotides in DNA that indicates where the RNA polymerase complex should bind to initiate transcription.
31
Initiation in Transcription
-the correct position for transcription to start is selected and the transcription machinery , composed of large-protein DNA complex is assembled
32
Elongation During Transcription
-the RNA polymerase complex works its way along the DNA molecule, synthesizing a strand of mRNA that is complementary to the anti-sense or template strand of DNA
33
In what direction does RNA polymerase work?
5' to 3' | *new nucleotides are added to the 3' end with hydroxyl*
34
As soon as the RNA polymerase complex starts to move along the DNA..what can happen?
A second RNA polymerase complex can bind to the promoter region and start to synthesize another RNA molecule.
35
Termination During Transcription
- specific nucleotide sequences in the DNA template serve as the signal to stop transcription - RNA polymerase detaches from DNA strand - new mRNA strand is released and DNA double helix reforms
36
What must mRNA undergo before it is transported across the nuclear membrane into the cytoplasm?
It must undergo modification.
37
Precursor mRNA (pre-mRNA)
-mRNA that has not undergone processing
38
Mature mRNA
-mRNA that has undergone processing
39
What are the two ways that mRNA is modified?
- addition of 5' cap - addition of 3' poly-A tail - removal of introns
40
5' Cap
-modified form of a G nucleotide; added to the 5' end of an mRNA
41
3' Poly-A Tail
A series of A nucleotides added to the 3' end of mRNA
42
Introns
Non-coding regions of genes.
43
Exons
Coding regions of genes
44
Splicing
In mRNA, a process of excising out the introns and combining in the exons.
45
What is responsible for splicing?
-snRNPs (snurps)
46
Alternative Splicing
-when only certain exons are used to form a mature RNA transcript
47
Transfer RNA (tRNA)
An RNA molecule that links the codons on mRNA to the corresponding amino acid for protein synthesis. *cloverleaf shape with anticodon on bottom and amino acid on top*
48
Anticodon Loop
A triplet of bases positioned at one end of a tRNA that recognizes and base-pairs with a codon on mRNA during protein synthesis.
49
Acceptor Stem
The 3' end of a tRNA molecule that is the site of attachment for a particular amino acid, based on the anticodon
50
What direction are anticodon written in?
3' to 5'
51
Aminoacyl-tRNA Synthetase
The enzyme responsible for attaching an amino acid to a tRNA
52
Ribosome
A cell structure composed of proteins and rRNA that provides the site where protein synthesis occurs.
53
Ribosomal RNA (rRNA)
The RNA that is associated with proteins in the ribosome.
54
Two Sub-Units of Ribosome
Large Sub-Units: 60S | Small Sub-Unit: 40S
55
What are the binding sites on the ribosomes called?
A Site: Acceptor Site, where new tRNA's enter the ribosome | P Site: Peptide Site, where tRNA moves to allow next tRNA to enter, forms the peptide bond
56
Polyribosome
A structure composed of multiple ribosomes along a strand of mRNA.
57
Initiation During Translation
- initiation factors assemble the small ribosomal sub-unit, mRNA, initiator tRNA, and large ribosomal sub-unit - small RSU attaches to mRNA at start codon (AUG) - initiator tRNA binds to AUG codon - large RSU joins to form active ribosome
58
Start Codon
A triple of three bases that specifies the first amino acid of a protein.
59
Reading Frame
Collectively, the codons of mRNA that are read to produce an amino acid sequence; it is set by the start codon.
60
Elongation During Translation
- as tRNA leave through the exit site, new tRNA bind to the A site - as tRNA move to the P site a peptide bond is formed between the first and second amino acids
61
Peptide Bond
A covalent bond formed between two amino acids during protein synthesis.
62
Termination During Translation
- occurs when stop codon is reached on mRNA (UGA,UAG,UAA) - polypeptide and components of machinery are separated - release factor cuts the polypeptide from the last tRNA
63
Mutation
A permanent change in the nucleotide sequence of a cell's DNA that is inherited
64
Single-Gene Mutation
A mutation that involves changes in the nucleotide sequence of one gene.
65
Chromosomal Mutation
A mutation that involves changes in chromosomes, and may involve many genes.
66
Point Mutation
A mutation involving a single base pair substitution, insertion of deletion.
67
Substitution Mutation
A mutation that exchanges one base for another.
68
Deletion Mutation
- one or more base pairs on the DNA is removed or eliminated - changes the properties of the protein and can result in the production of a defective protein
69
Insertion Mutation
- one or more base pairs is added to the DNA sequence - results in an extra amino acid being coded for in the polypeptide sequence - can alter how the protein behaves
70
Frameshift Mutation
A mutation caused by the addition or deletion of a number of nucleotides not divisible by three, resulting in a change in the reading frame.
71
Three Types of Substitution Mutations
- Silent Mutation - Missense Mutation - Nonsense Mutation
72
Silent Mutation
A mutation that does not change the amino acid sequence of a protein.
73
Missense Mutation
A mutation that changes the amino acid sequence of a protein. *A different amino acid is coded, so sequence changes.*
74
Nonsense Mutation
- a mutation that shortens a protein by introducing a stop codon - causes polypeptide chain to be terminated prematurely
75
Types of Chromosomal Mutations
- deletion - duplication - inversions - translocations
76
Deletion in Chromosomal Mutations
-a section of the chromosome is deleted
77
Duplication in Chromosomal Mutations
-a section of the chromosome is repeated
78
Inversion in Chromosomal Mutations
-a section of the chromosome is broken and then re-inserted in the opposite direction
79
Translocations in Chromosomal Mutations
A fragment of DNA breaks off and joins at another place on the chromosome or on another chromosome.
80
Transposon
A short segment of DNA capable of moving within the genome of an organism; also called a jumping gene.
81
Spontaneous Mutations
-take place naturally in the cell as a result of normal molecule interactions
82
Mutagen
An event or substance that increases the rate of changes to the DNA sequence of an organism's genome.
83
Chemical Mutagen
A molecule that can enter the nucleus of a cell and induce mutations by reacting chemically with the DNA. eg. Nitrites, gasoline fumes, cigarette smoke
84
Physical Mutagen
A mutagen that physically changes the structure of DNA. | eg. X-rays, UV Radiation

4U BIO (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions