Brainscape's Knowledge GenomeTM

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


See full index

Cytogen > DNA Structure And Replication > Flashcards

DNA Structure And Replication Flashcards

1
Q

Sequence of DNA that tells a cell how to assemble amino acids into a particular protein

A

Gene

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

Single building block of DNA

A

Nucleotide

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

Nucleotide consists of

A

Deoxyribose
Phosphate group
Nitrogenous bases

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

(2) are_____, which have a two-ring structure

A

Adenine (A) and guanine (G)

purines

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

(2) are_____, which have a single-ring structure.

A

Cytosine (C) and thymine (T)

pyrimidines

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

are the information-containing parts of DNA because they form sequences.

A

bases

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

Nucleotides join into long chains when chemical bonds form between the deoxyribose sugars and the phosphates. This creates a continuous__________

A

sugar-phosphate backbone

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

The opposing orientation of the two nucleotide chains in a DNA molecule is called_____. It derives from the structure of the sugar-phosphate backbone._______ becomes evident when the carbons of the sugars are assigned numbers to indicate their positions in the molecule

A

antiparallelism

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

are the informational parts of nucleotides.

A

DNA bases

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

________of a nucleic acid consists of a 5-carbon sugar, a phosphate group, and an organic, nitrogenous base (G, A, C, or T).

A

nucleotide

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

These specific purine-pyrimidine couples are called

A

complementary base pairs

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

Chemical attractions called__________ hold the base pairs together.

They are weak individually, but over the many bases of a DNA molecule impart great strength.

_____hydrogen bonds join A and T, and_____ hydrogen bonds join G and C

A

hydrogen bonds

Two

three

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

DNA consists of two chains of_______.

A

nucleotides

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

(a)_______ hold the nitrogenous bases of one strand to the nitrogenous bases of the second strand (dotted lines).

Note that the sugars point in opposite directions—that is, the strands are_____.

A

Hydrogen bonds

antiparallel

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

The_______ nature of the DNA double helix becomes apparent when the carbons in the sugar are numbered.

A

antiparallel

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

The double-stranded, helical structure of DNA gives it great strength—____times the strength of single-stranded DNA, C which would not form a helix.

A

50

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

the DNA coils around proteins called

A

Histones

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

The bead part is called a_________. It is a little like wrapping a very long, thin piece of thread around your fingers, to keep it from unraveling and tangling.

A

nucleosome

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

DNA wraps at several levels, until it is compacted into a______.

Specifically, a nucleosome forms around packets of____ histone proteins (a pair of each of four types).

A

chromosome

eight

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

Altogether, the chromosome substance is called_______, which means “colored material.”

A

chromatin

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

Chromatin is not just DNA; it is about 30 percent______,
30 percent_______,
30 percent_____, and
10 percent______

A

histone proteins

DNA binding proteins

DNA

RNA

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

The DNA double helix is______, its strands running in an opposite head-to-toe manner.

A

antiparallel

23
Q

DNA winds tightly about______, forming______, which in turn wind tighter, forming_______.

A

histone proteins

nucleosomes

chromatin

24
Q

DNA has _______ replication because each new DNA double helix conserves half of the original

A

semiconservative

25
Q

some researchers suggested that DNA might replicate in any of three possible ways:

■

■with one double helix specifying creation of a second double helix, and

■with a double helix shattering into pieces that would join with newly synthesized DNA pieces to form two molecules.

A

semiconservative

conservative

dispersive

26
Q

T or F

DNA is highly condensed

A

True!

27
Q

DNA spools around_____ of four types of histone proteins, forming_____.

A

octets

nucleosomes

28
Q

DNA replication occurs during _____ phase of the cell cycle

A

S phase

29
Q

Enzymes called______ unwind and hold apart replicating DNA, enabling other enzymes to guide the assembly of a new DNA strand.

A

helicases

30
Q

Human DNA replicates about___ bases per second

A

50

31
Q

A site where DNA is locally opened, resembling a fork, is called a

A

replication fork

32
Q

DNA replication begins when a_____ breaks the hydrogen bonds that connect a base pair

A

helicase

33
Q

hold the two strands apart.

A

Binding proteins

34
Q

______, then attracts complementary RNA nucleotides to build a short piece of RNA, called an_____, at the start of each segment of DNA to be replicated.

A

primase

RNA primer

35
Q

The RNA primer is required because the major replication enzyme,______, can only add bases to an existing nucleic acid strand. (A______ is an enzyme that builds a polymer, which is a chain of chemical building blocks.)

A

DNA polymerase (DNAP)

polymerase

36
Q

_________attracts DNAP, which brings in DNA nucleotides complementary to the exposed bases on the parental strand; this strand serves as a mold, or template.

New bases are added one at a time, starting at the______

A

RNA primer

37
Q

unwinds parental double helix.

A

Helicase

38
Q

stabilize separate strands.

A

Binding proteins

39
Q

adds short primer to template strand.

A

Primase

40
Q

binds nucleotides to form new strands.

A

DNA polymerase

41
Q

joins Okazaki fragments and seals other nicks in sugarphosphate backbone.

A

Ligase

42
Q

________ proofreading activity checks and replaces incorrect bases.

A

DNA polymerase

43
Q

Continuous strand synthesis continues in a _____ direction.

A

5′ to 3′

44
Q

Discontinuous synthesis produces Okazaki fragments on the _____template.

A

5′ to 3′

45
Q

DNAP works directionally, adding new nucleotides to the exposed___′ end of the sugar in the growing strand.

Overall, replication proceeds in a ___________ direction, because this is the only chemical configuration in which DNAP can add bases.

A

3”

5′ to 3′

46
Q

______then seals the sugar-phosphate backbones of the pieces, building the new strand.

These pieces, up to 150 nucleotides long, are called_______, after their discoverer

A

ligase

Okazaki fragments

47
Q

also “proofreads” as it goes, excising mismatched bases and inserting correct ones.

It also removes the RNA primer and replaces it with the correct DNA bases.

A

DNA polymerase

48
Q

________, rewinds any sections of the DNA molecule that remain unwound

A

annealing helicase

49
Q

seal the entire sugar-phosphate backbone.

It comes from a Latin word meaning “______.”

A

ligases

to tie

50
Q

T or F

DNA replication occurs simultaneously at several points on each chromosome, and the pieces join.

A

True!

51
Q

At each initiation site,____ directs synthesis of a short RNA primer, which DNA eventually replaces.______ adds complementary bases to the RNA primer.____ joins the sugar-phosphate backbone.

A

primase

DNA polymerase

Ligase

52
Q

DNA is highly coiled, and complexed with protein to form_____.

A

chromatin

53
Q

_______form as hydrogen bonds break between base pairs.

____builds short RNA primers, which DNA sequences eventually replace.

Next _______ fills in DNA bases, and ligase seals the sugar-phosphate backbone.

A

Replication forks

Primase

DNA polymerase

Cytogen (34 decks)

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