Nucleic acids

Question 1

What are nucleotides

Answer 1

nucleotides are monomers consisting of three molecules:

1. a pentose sugar
2. nitrogenous base
3. phosphate group

Question 2

What type of reaction forms a nucleotide

Answer 2

condensation reaction

Question 3

What does DNA stand for

Answer 3

Deoxyribonucleic acid

Question 4

What does RNA stand for

Answer 4

ribonucleic acid

Question 5

Describe the structure of DNA

Answer 5

double helix made up of two polynucleotide strands

Question 6

What type of bond is formed between bases

Answer 6

Hydrogen bonds

Question 7

What is the relationship between the polynucleotide strands of one DNA molecule

Answer 7

1. The polynucleotide strands are anti-parallel
2. one strand runs from 3’ to 5’
3. the other strand runs from 5’ to 3’

Question 8

what does 3’ or 5’ mean

Answer 8

(3 prime or 5 prime)
5’ means carbon 5 is available for a phosphate to bind
3’ means carbon 3 is available for a phosphate to bind

Question 9

where is DNA stored

Answer 9

nucleus

Question 10

what structures are formed from DNA

Answer 10

chromosomes

Question 11

what are the four bases (DNA)

Answer 11

GCAT

guanine, cytosine, adenine, thymine

Question 12

What 5 elements make up DNA

Answer 12

Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus

Question 13

what does Adenine pair with (DNA)

Answer 13

Thymine

Question 14

what does Thymine pair with (DNA)

Answer 14

Adenine

Question 15

what does cytosine pair with

Answer 15

Guanine

Question 16

what does Guanine pair with

Answer 16

Cytosine

Question 17

what does Adenine pair with (RNA)

Answer 17

Uracil

Question 18

What are the four bases (RNA)

Answer 18

guanine, cytosine, adenine, Uracil

Question 19

Why do the bases only pair with specific bases

Answer 19

they are complimentary in size and shape

Question 20

What type of bond is between A and T

Answer 20

Hydrogen double bond

Question 21

What type of bond is between G and C

Answer 21

Hydrogen triple bond

Question 22

What type of bonds are between nucleotides

Answer 22

Phosphodiester bonds

Question 23

What is a nucleotide made up of (DNA)

what shapes represents them

Answer 23

1. Phosphate group (circle)
2. Deoxyribose sugar (pentagon)
3. Nitrogenous base (rectangle)

Question 24

What is a nucleotide made up of (RNA)

what shapes represent them

Answer 24

1. Phosphate group (circle)
2. Ribose sugar (pentagon)
3. Nitrogenous base (rectangle)

Question 25

explain the condensed structures of DNA | Double helix - chromosome

Answer 25

1. Double helix 2. nucleosomes, double helix wraps around histone 3. nucleosomes condense to form unwound chromatin 4. unwound chromatin winds to form condensed chromatin 5. condensed chromatin condenses more and forms a single chromosome

Question 26

What are the 4 differences between RNA & DNA

Answer 26

1. RNA is a single stranded poly nucleotide whereas DNA is double stranded 2. Thymine is replaced by Uracil RNA (GCAU) DNA (GCAT) 3. RNA is ribose sugar, DNA is deoxyribose sugar 4. RNA has a much shorter strand than DNA

Question 27

REMEMBER: | DNA can bind with RNA

Answer 27

DNA can bind with RNA

Question 28

What stage does DNA replication occur at

Answer 28

Interphase

Question 29

Describe the first stage of DNA replication

Answer 29

The DNA double helix is ready to be replicated. The DNA strand unwinds ONLY in the section that needs to be replicated

Question 30

Describe the second stage of DNA replication

Answer 30

The enzyme DNA helicase causes the two strands of DNA to separate by breaking the hydrogen bonds between complimentary bases. DNA helicase runs from 3' t 5' as the active site is complimentary to 3'

Question 31

Describe the third stage of DNA replication

Answer 31

Free floating nucleotides are attracted to their complimentary bases, hydrogen bonds between them form naturally. The enzyme DNA polymerase creates the phosphodiester bonds in the backbone (condensation reaction)

Question 32

Describe the fourth stage of DNA replication

Answer 32

The two identical strands of DNA are formed. In each helix one strand is an original strand and one is a new strand.

Question 33

what is the model for DNA replication called

Answer 33

semi-conservative replication

Question 34

what is the structure of ATP

Answer 34

Adenine - a nitrogen containing base Ribose phosphates

Question 35

what is ATP used in

Answer 35

``` metabolic processes movement active transport secretion activation of molecules ```

Question 36

What causes water molecules to stick together

Answer 36

hydrogen bonds between the positive poles on one water molecule and the negative charges on another (as water is dipolar due to the pos charge on the hydrgoen and the neg charge on oxygen)

Question 37

what is water needed for

Answer 37

- as a solvent, dissolves other substances | - metabolism, used to break down substances in hydrolysis