Nucleic Acid Structure

Question 1

What is transcription?

Answer 1

DNA transcribed to RNA

Question 2

What is translation?

Answer 2

RNA translated to protein

Question 3

What is gene expression?

Answer 3

Transcription and translation (DNA to protein)

Question 4

What is reverse transcription?

Answer 4

RNA to DNA (only retroviruses like HIV can do this)

Question 5

Where does transcription occur?

Answer 5

In the nucleus

Question 6

Where does translation occur?

Answer 6

In the cytoplasm

Question 7

Where does DNA replication occur?

Answer 7

In the nucleus

Question 8

What is the difference between gene expression and replication?

Answer 8

Question 9

What are the 2 purines?

Answer 9

1) adenine
2) guanine

Pure As Gold

Note: purines have a shorter name, but larger structure

Question 10

What do nucleotides consist of?

Answer 10

Base, sugar, and phosphate group(s)

Question 11

What are the 3 pyrimidines?

Answer 11

1) cytosine
2) uracil
3) thymine

CUT = mnemonic to remember

Note: pyrimidines have a longer name, but smaller structure

Question 12

What bases are found in DNA?

Answer 12

A, T, C, G

Question 13

What bases are found in RNA?

Answer 13

A, U, C, G

Question 14

What is a nucleoside?

Answer 14

nitrogen base + sugar

Question 15

Is RNA single or double stranded?

Answer 15

single stranded

Question 16

Is DNA single or double stranded?

Answer 16

double stranded

Question 17

What bond connects the bases in DNA?

Answer 17

hydrogen bonds

3 hydrogen bonds between C-G
2 hydrogen bonds between A-T (would be A-U in RNA)

Question 18

What bond holds the base to sugar?

Answer 18

N- glycosidic bond

Question 19

What bond holds the phosphate to the sugar?

Answer 19

ester bond

Question 20

What bond uses 2 oxygens from phosphate to connect to 2 sugars?

Answer 20

phosphodiester bond

Question 21

What bond is between phosphate groups?

Answer 21

phosphoanhydride bond

Question 22

What bond in DNA is more stable C-G or A-T?

Answer 22

C-G because its 3 hydrogen bonds (A-T is only 2 hydrogen bonds)

so more C-G= DNA is more stable

Question 23

What are the 2 major rules/properties of dsDNA?

Answer 23

1) complementary pairs (A-T and C-G)
2) antiparallel sugar phosphate backbone

Question 24

The correct structure of DNA components can be presented as:
A) phosphate-base-sugar
B) phosphate-sugar-base
C) base-phosphate-sugar
D) phosphate-sugar-phosphate-base
E) base-sugar-phosphate base

Answer 24

B) phosphate-sugar-base

Question 25

What are the Chargaff rules?

Answer 25

dsDNA ONLY - % of A= % of T - % of G= % of C - % of purines= % of pyrimidines

Question 26

What is the complementary sequence of 5' TAGAC 3'?

Answer 26

5' GTCTA 3'

Question 27

According to Chargaff's rules, which of the following statements about dsDNA is true? A) A=T and C=G B) A+G= C+T C) A+T = C+G D) A and B E) A, B, and C

Answer 27

D) A and B

Question 28

What is primary structure in DNA?

Answer 28

the linear arrangement of the nucleotides in the polynucleotide

Question 29

What bond forms primary structure in DNA?

Answer 29

phosphodiester bond

Question 30

What structure is DNA double helix?

Answer 30

secondary structure

Question 31

What is a right handed double helix?

Answer 31

-pentose sugar and phosphate face the outside environment (towards water) -complementary base pairing -antiparallel -10 residues (nucleotides) per turn of DNA

Question 32

There are 4 DNA conformations found in nature. Which type is predominated in cells?

Answer 32

B-DNA

Question 33

What is B-DNA?

Answer 33

-dominant DNA form found in nature -right handed helix -sugar phosphate on the outside and bases on the inside (sugar phosphates like water)

Question 34

What is chromatin?

Answer 34

-DNA + protein -complex macromolecule found in cells, consisting of DNA and protein

Question 35

What is nucleosome?

Answer 35

DNA + histone octamer -basic unit of DNA packaging in eukaryotes -consisting of a segment of DNA wound in sequence around 8 histone protein cores

Question 36

Besides DNA and RNA, what are the other forms/functions of nucleotides?

Answer 36

-energy carriers (ATP, GTP, CTP, UTP) -coenzymes (FAD, NAD, CoA) -cellular communication with cAMP (carries messages from cell surface when hormone attaches)

Question 37

are coenzymes active?

Answer 37

yes! They help enzymes function, its the active form of vitamins

Question 38

What are the energy carriers we learned about?

Answer 38

-ATP -GTP -CTP -UTP can also be diphosphate or monophosphate, or have different base than adenine

Question 39

anything ending with -ase=

Answer 39

enzyme

Question 40

anything ending with -ose=

Answer 40

sugar

Question 41

What is another name for riboflavin?

Answer 41

vitamin B2

Question 42

What is the active form of riboflavin (vit B2)?

Answer 42

flavin adenine dinucleotide (in electron transfer), also known as FAD is the active form/coenzyme will catch hydrogens for energy = FADH2 dinucelotide= 2 nucleotides (sugar, P, and base) -the base here would be riboflavin

Question 43

What is another name for nicotinamide?

Answer 43

vit B3, or niacin

Question 44

What is the active form of nicotinamide (vit B3, or niacin)?

Answer 44

nicotinamide adenine dinucleotide (NAD) (transfers hydride)

Question 45

What is another name for pantothenate?

Answer 45

vit B5

Question 46

What is the active form of pantothenate (vit B5)?

Answer 46

CoA (coenzyme A, transfers an acyl group)

Question 47

What are the 2 types of hormones?

Answer 47

lipid and protein lipid hormones can easily get through cell membrane because of phospholipid bilayer, for ex: steroids protein hormones like insulin and glucagon cannot penetrate cell membrane and need a 2nd messenger to get through

Question 48

What is the major function of nucleotides?

Answer 48

make RNA and DNA