Exam 3 Flashcards

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

Monomer of DNA?

A

Nucleotides

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

What are Pyrimidines and give examples?

A

Nitrogenous base with one ring

C (cytosine)
T (Thymine)

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

What are purines and give examples?

A

Nitrogenous bases with 2 rings

A (adenine)
G (guanine)

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

Describe the structure of a DNA

A

Nitrogenous base (A,T,G,C)
Deoxyribose Sugar
Phosphate group

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

The backbone of dna is the _____

A

Sugar-phosphate backbone

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

What is found at the 5’ end and the 3’ end?

A

5’: Phosphate group

3’: OH-

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

What are the nitrogenous base pairings?

A

Adenine & Thymine
Guanine & Cytosine

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

Nitrogenous bases in DNA vs RNA

A

RNA swaps the Thymine in DNA for Uracil
DNA - A, T, G, C
RNA - A, U, G, C

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

The sugar in DNA is _______

A

deoxyribose

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

The sugar in RNA is _______

A

ribose

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

How are the nitrogenous bases connected within the double helix?

A

Hydrogen bonds

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

Describe mRNA

A

Messenger RNA
Translates DNA into form readable for cells. (T —> U)

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

Describe rRNA

A

Ribosomal RNA
Helps mRNA bind to a spot on ribosome

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

RNA that acts as enzyme is called _______

A

Ribozymes

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

Describe tRNA

A

Transfer RNA
Brings amino acids to ribosome and ensures it is the amino acid specified by mRNA

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

How do regulatory mRNA (miRNA & siRNA) maintain homeostasis?

A

Bind to mRNA molecules and reduce their stability or interfere with the translation

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

Topoisomers function

A

Prevents supercoiling
Prevents double helix from getting to tightly wound as it is being opened

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

Helicase function

A

Breaks the hydrogen bonds that bind the nitrogenous bases in DNA.
Splits the DNA.

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

Function of RNA Primer
What’s synthesizes primer?

A

Begins the synthesis of DNA strands
-Primase

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

What is DNA polymerase?

A

Enzyme that creates new DNA by adding nucleotides to growing DNA chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In what direction do nucleotides get added?

A

5’ —-> 3’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the replication fork?

A

The Y-shape created by the splitting of the DNA helix

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

Describe the leading strand

A

5’ –> 3’ moves in the same direction as the DNA polymerase
Complimentary strand moves toward the replication fork

24
Q

Describe the lagging strand

A

Moves away from the fork
Made in fragments because as the fork moves forward, the DNA polymerase has to detach and reattach on newly formed DNA

25
Q

What is the Okazaki Fragments?

A

The small fragments made on the lagging strand. New primer is required for each fragment

26
Q

Main function of DNA polymerase III?

A

Makes the bulk of new DNA

27
Q

Main function of DNA polymerase I?

A

Removes RNA primers and replaces it with DNA

28
Q

Basic DNA replication is called semi-conservative. What does this mean?

A

Each new strand of DNA contains one old and one new strand.

29
Q

What is conservative DNA replication?

A

Replication results in one molecule consisting of both old strands and another molecule containing 2 new strands

30
Q

Describe dispersive DNA replication

A

2 DNA molecules are formed as mixtures/patchwork of both the Parent & Daughter DNA

31
Q

What enzyme is responsible for proofreading?

A

DNA polymerase

32
Q

What is the function of Telomeres and how can you identify them?

A

Telomeres act as caps to protect internal chromosomes. (prevent loss of genes)

They are repetitive regions found at the end of some chromosomes
5’-TTAGGG-3’

33
Q

What is the function of Telomerase?
How does it work?

A

Enzyme that prevents telomere shortening.
Synthesis of telomeres by creating DNA by using RNA as a template

34
Q

Main idea of transcription

A

Copies DNA sequence from gene using RNA alphabet (A –> U)
Creates mRNA

35
Q

What is gene expression?

A

Info from a gene is used to construct a protein

36
Q

What is RNA polymerase?

A

Uses single strand of DNA as template to synthesize a complimentary strand of RNA

37
Q

RNA polymerase vs DNA polymerase

A

DNA polymerase is the enzyme used in DNA replication whereas RNA polymerase is the enzyme used in transcription

38
Q

Describe initiation and the promoter region

A

Initiation is the first step in gene expression in which RNA polymerase separates the DNA into single strands at the promoter.
Promoter - Tells RNA polymerase where to bind to

39
Q

Describe elongation and what information the RNA transcript contains

A

Elongation is when a complimentary (coding) strand is created from a template strand. The RNA transcript copies the coding strand swapping the T –> A.

40
Q

What are terminators?

A

Sequences on genes that signal the RNA polymerase to end the transcript

41
Q

Which strand does RNA transcript bind to?

A

Template strand

42
Q

What is the coding strand?

A

The complimentary strand

43
Q

Where is mRNA found?

A

Nucleus

44
Q

What is translation?

A

Converts information from mRNA into proteins at the ribosome

45
Q

What is the start codon?

A

AUG

46
Q

Define genetic code

A

Collection of the codon-amino acid relationships

47
Q

What is the central dogma?

A

Process of information flow from genes to proteins
DNA -> RNA -> Proteins

48
Q

(Substitution Mutation) Silent mutations

A

Has no effect on the amino acid

49
Q

(Sub. Mutation) Nonsense mutations

A

Results in a stop codon where it shouldn’t be

50
Q

(Sub. Mutation) Missense mutations

A

Changes the amino acid specified by the codon

51
Q

Frameshift mutations

A

Insertion or deletion of one or more bases

52
Q

What is an inducible operon?

A

A type of operon that is turned “off” until a small molecule called an inducer binds to it and turns it on.

53
Q

Describe lac operon

A

An inducible operon responsible for enzymes that metabolize sugar lactose

54
Q

What are repressible operons?

A

Type of operon that is turned “off” until small molecule called corepressor turns it on.

55
Q

Describe trp operon

A

Repressible operon responsible for enzyme that synthesizes amino acid tryptophan

56
Q

What is DNA Cloning and how does it work?

A

Identical copies of a piece of DNA
Gene is cut from DNA strands and attached to a plasmid that is given to a bacteria to reproduce it.

57
Q

DNA Ligase

A

An enzyme that joins strands of DNA together