Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIO 101 > Ch. 13 and 14 > Flashcards

Ch. 13 and 14 Flashcards

1
Q

What are the four nitrogenous bases found in DNA?

A
  1. thymine
  2. guanine
  3. cytosine
  4. adenine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the four nitrogenous bases found in RNA?

A
  1. uracil
  2. gunaine
  3. cytosine
  4. adenine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the complementary bases in DNA?

A
  1. adenine + thymine (A+T)
  2. guanine + cytosine (G+C)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the complementary bases in RNA?

A
  1. adenine + uracil (A+U)
  2. guanine + cytosine (G+C)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What kind of bond holds nitrogenous base pairs together?

A

hydrogen bonds

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

What discovery was Chargaff best known for?

A

concluding that in natural DNA, the number of G=C and the number of A=T

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

What are purines?

A

one of two nitrogenous bases characterized by a 6-membered ring fused to a 5-membered ring

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

Which nitrogenous bases are purines?

A

adenine and guanine

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

What are pyrimidines?

A

one of two types of nitrogenous bases characterized by a 6-membered ring

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

Which nitrogenous bases are pyrimidines?

A

cytosine, thymine, and uracil

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

What is a semiconservative model?

A

a type of DNA replication in which the replicated double helix consists of one old strand and one newly made strand

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

What is helicase?

A
  • an enzyme that untwists the double helix of DNA at replication forks
  • separates the two strands and makes them available as template strands
  • “scissors” that cut DNA in half
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is DNA polymerase?

A
  • an enzyme that catalyzes the elongation of new DNA by the addition of nucleotides to the the 3’ end of an existing chain
  • “builders” that assemble nucleotides on DNA molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is DNA ligase?

A
  • a linking enzyme that fills in the gaps made from Okazaki fragments to make on continuous strand
  • “glue” that patches DNA together
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a replication bubble?

A

a loop that is generated by the unwinding of the double helix

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

What is a replication fork?

A

a Y-shaped region on a replicating DNA molecule where the parental strands are being unwound and new strands are being synthesized

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

In what direction is DNA always synthesized?

A

5’-3’ direction

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

What is a leading strand?

A

the new complementary DNA strand synthesized continuously along the template strand toward the replication fork

5’-3’ direction

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

What is a lagging strand?

A

a discontinuously synthesized DNA strand that elongates by means of Okazaki fragments synthesized away from the replication fork

5’-3’ direction

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

What is a lagging strand?

A

a discontinuously synthesized DNA strand that elongates by means of Okazaki fragments synthesized away from the replication fork

5’-3’ direction

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

What are Okazaki fragments?

A
  • short segments of DNA synthesized away from the replication fork on a template strand
  • segments are joined together to make up the lagging strand of newly synthesized DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the flow of genetic information?

A
  • the “flow” of genetic info from DNA to RNA to proteins
  • through transcription and translation, info from genes is used to make proteins

“central dogma”

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

What is the flow of genetic information?

A
  • the “flow” of genetic info from DNA and RNA
  • through transcription and translation, info from genes is used to make proteins

“central dogma”

23
Q

What are triplets in genetic code?

A

refers to a set of 3 nucleotide bases that code for a certain amino acid

read 3 at a time to account for all 20 possible amino acids

24
What is genetic code?
* refers to the instructions contained in a gene that tell a cell how to make a specific protein * uses 4 nucleotide bases in various ways to create 3-letter codons that specify which amino acid must be made
25
What is transcription?
* the synthesis of RNA using a DNA template * occurs in the nucleus of eukaryotes
26
What is RNA polymerase?
* an enzyme that links ribonucleotides into a growing RNA chain during transcription * starts transcribing at the promoter
27
What are the 3 stages of transcription?
1. initiation 2. elongation 3. termination
28
What is initiation? | transcription
* RNA polymerase binds to DNA's promoter to begin transcription * promoter tells RNA polymerase where to settle itself on DNA and begin transcribing
29
What is elongation? | transcription
* RNA strand gets longer due to the addition of new nucleotides * RNA polymerase walks along the template strand in 3'-5' direction
30
What is termination? | transcription
* the process of ending transcription in which RNA gets signals to stop transcribing * happens once the polymerase transcribes a sequence of DNA known as the terminator
31
What is messenger RNA? | mRNA
a type of RNA whose job is to carry protein info from the nucleus to the cytoplasm, where polypeptides are formed
32
What is RNA splicing?
a process that removes introns from pre-RNA and joins exons together in order to enable translation
33
What are introns?
non-coding, intervening sequences within a primary transcript that is removed during RNA processing
34
What are exons?
sequences within a primary transcript that remains in the RNA after RNA processing
35
What is transfer RNA? | tRNA
* functions as a translator between nucleic acid and protein languages by picking up a specific amino acid and carrying it to the ribosome * recognizes the appropriate codons in the mRNA
36
What is an anti-codon?
a group of 3 bases on a tRNA molecule that is complementary to an mRNA codon
37
What is translation?
* the synthesis of a polypeptide using the genetic info encoded in an mRNA molecule * includes a change of "language" from nucleotides to amino acids | occurs in ribosomes
38
How many ribosomal subunits are there?
2; one big and one small | come from the cell's nucleolus
39
What is the P site?
* holds the tRNA carrying the growing polypeptide chain * peptidyl-tRNA | middle site
40
What is the P site?
* holds the tRNA carrying the growing polypeptide chain * peptidyl-tRNA | middle site
41
What is the A site?
* holds the tRNA carrying the next amino acid to be added to the polypeptide chain * aminioacyl tRNA | entrance site
42
What is the E site?
the place where the discharged tRNAs leave the ribosome | exit site
43
What are the 3 stages of translation?
1. initiation 2. elongation 3. termination
44
What is initiation? | translation
ribosome gets together with the mRNA and the first tRNA so translation can begin
45
What is elongation? | translation
* amino acids are brought to the ribosome by tRNAs and linked together to form a chain * composed of 3 steps: codon recognition, peptide bond formation, and translocation
46
What is termination?
the finished polypeptide is released to go and do its job in the cell
47
What are the 3 steps of elongation?
1. codon regonition 2. peptide bond formation 3. translocation
48
What are mutations?
changes in the nucleotide sequence of an organism's DNA (or in a virus)
49
What are the 2 types of small-scale nucleotide changes?
1. substitution 2. insertion/deletion
50
What is nucleotide-pair substitution?
a type of point mutation that replaces one nucleotide and its partner with another pair of nucleotides
51
What is insertion/deletion?
additions or losses of nucleotides in a gene
52
What are silent mutations?
substitutions that have no observable effect on the phenotype | ex: (in a gene) a codon that codes for the same amino acid
53
What are missense mutations?
substitutions that result in a codon that codes for a different amino acid
54
What are nonsense mutations?
mutations that change an amino acid codon to one of the 3 stop codons --> shorter and usually nonfunctional protein
55
What are mutagens?
anything capable of causing a mutation

BIO 101 (11 decks)

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