Nucleic Acids and ATP

Question 1

functions of DNA

Answer 1

replicate to produce an exact copy before cell division
carry code for protein synthesis

Question 2

types of RNA

Answer 2

mRNA = messenger RNA
tRNA = transfer RNA
rRNA = ribosomal RNA

Question 3

which RNA is functional RNA?

Answer 3

tRNA and rRNA

Question 4

monomer and polymer of nucleic acids

Answer 4

monomer = nucleotide
polymer = polynucleotide

Question 5

what bond joins nucleotides in a polynucleotide chain?

Answer 5

phosphodiester bond

Question 6

where is DNA found?

Answer 6

nucleus of cell

Question 7

where is RNA found?

Answer 7

nucleus and cytoplasm of cell

Question 8

describe the structure of a general nucleotide

Answer 8

a pentose sugar, with a nitrogenous base and one or more phosphate groups attached

Question 9

three types of nucleotides

Answer 9

DNA, RNA and ATP

Question 10

differences between DNA and RNA structure

Answer 10

• DNA has deoxuribose sugar, while RNA has ribose
• DNA has nitrogenous bases ATCG while RNA has bases AUCG, with uracil instead or thymine
• DNA has 2 polynucleotid strands while RNA has 1

Question 11

purine bases

Answer 11

adenine and guanine

Question 12

feature of purine bases

Answer 12

double ring

Question 13

pyrimidine bases

Answer 13

thymine, cytosie and uracil

Question 14

feature of pyrimidine bases

Answer 14

single ring

Question 15

why does DNA have a 1:1 ratio of purine:pyrimidine bases

Answer 15

purine always base pairs with pyrimidine
ensures 2 sugar-phosphate backbones completely parallel to each other, always 3 rings apart

Question 16

what are the complementary base pairs and the number of H- bonds between them?

Answer 16

adenine-thymine (2 bonds)
cytosine-guanine (3 bonds)

Question 17

function of DNA having a coiled structure

Answer 17

this protects the H-bonds between strands therefore reducing corruption of the genetic code

Question 18

function of a strong sugar-phosphate backbone

Answer 18

gives strength to the DNA molecule

Question 19

function of DNA being a long molecule

Answer 19

DNA can store a lot of genetic information (genes)

Question 20

function of the many weak H-bonds in DNA

Answer 20

makes DNA a stable molecule

Question 21

function of weak H-bonds holding polynucleotide strands together

Answer 21

strands can be separated for transcription and replication

Question 22

function of seuencing of bases in DNA

Answer 22

allows information to be stored

Question 23

describe the structure of a DNA molecule

Answer 23

a DNA molecule is a double helix structure made up of two polynucleotide strands each with a strong sugar-phosphate backbone made up of nucleotides joined by phosphodiester bonds. these strands are joined by weak hydrogen bonds which form between complementary base pairs (A-T and C-G)

Question 24

structure of an ATP nucleotide

Answer 24

an ATP molecule contains a ribose sugar with a nitrogenouse base adenine and three phosphate groups (a triphosphate).

Question 25

ATP

Answer 25

adenosine triphophate

Question 26

4 features of ATP hydrolysis

Answer 26

1. forms ADP and Pi 2. is an exergonic reaction 3. releases energy by breaking bond between 2nd and 3rd phosphate groups 4. is catalysed by ATP hydrolase

Question 27

4 features of ATP synthesis

Answer 27

1. uses ADP and Pi 2. is an endergonic reaction 3. stores energy in high energy bond between 2nd and 3rd phosphate groups 4. is catalysed by ATP synthase

Question 28

roles of ATP

Answer 28

* energy donor molecule * immediate source of energy * universal energy molecule

Question 29

ATP as a universal energy molecule

Answer 29

all reactions, all cells, all organisms use ATP

Question 30

6 advantages of ATP over glucose

Answer 30

1. only requires 1 enzyme for hydrolysis 2. releases energy in usable quantities 3. easily transported across organelle membranes 4. water soluble 5. doesn't need to be stored 6. easy recycling between ATP and ADP + Pi

Question 31

why is it an advantge that ATP releases energy in usable quantities?

Answer 31

hydrolysis of glucose would result in a surplus

Question 32

why is it an advantage that ATP doest need to be stored?

Answer 32

glucose must be stored as glycogen or starch

Question 33

# energy needed, energy released, coupled, Pi, synthesis 5 steps of ATP recycling

Answer 33

1. when energy needed by cell, ATP hydrolysed into ADP + Pi (catalysed by ATP hydrolase) 2. hydrolysis of phosphate bond rleases energy 3. ATP hydrolysis coupled to other energy-requiring reactions in cell so energy released is used directly, not lost as heat 4. released Pi can be added to another compound in phosphorylation, often making compound more reactive 5. ATP can be resynthesised in a condensation reactionbetween ADP + Pi, during PS and RS, catalysed by ATP synthesis