ATP and DNA

Question 1

What are Exons?

Answer 1

Regions of DNA that codes for proteins

Question 2

What are Introns?

Answer 2

Non coding blocks of nucleotides repeated to cause genetic variation

Question 3

What type of genes have introns?

Answer 3

Eukaryotic Genes (discontinuous genes)

Question 4

What type of genes have no introns?

Answer 4

Prokaryotic Genes (continuous genes)

Question 5

What is the difference between DNA and RNA?

Answer 5

DNA consists of Adenine, THYMINE, Guanine and Cytosine

RNA consists of Adenine, URACIL, Guanine and Cytosine

Question 6

What is the function of DNA? (2)

Answer 6

1. Replication in diving cells (replication allows accurate copying of DNA for cell division)
2. Carries the genetic information for proteins synthesis

Question 7

What is DNA?

Answer 7

Large molecules made of several nucleotides

Question 8

What is a pryrimidine?

Answer 8

A single ring of carbon and nitrogen consisting of Cytosine and Thymine

Question 9

What is a purine?

Answer 9

A double ring of carbon and nitrogen consisting of Guanine and Adenine

Question 10

What is the monomer of DNA?

Answer 10

A nucleotide

Question 11

What is the structure of DNA?

Answer 11

Phosphate group bonded to deoxyribose bonded to Nitrogenous base

Question 12

What is DNA replication?

Answer 12

When the DNA is coped and 2 of each molecules is present in the nucleus

Question 13

Why does DNA replication take place?

Answer 13

The DNA needs to double in quantity before cell division by mitosis or meiosis

Question 14

When does DNA replication take place?

Answer 14

During the interphase stage of cell division

Question 15

Where does DNA replication take place?

Answer 15

In the nucleus

Question 16

What is the first stage to DNA replication?

Answer 16

1. One end of the DNA unwinds due to DNA helicase, this is a replication fork. The DNA helicase attaches to one end of the DNA and travels along the molecules. It unwinds the double helix and breaks the Hydrogen bonds between the complementary base pairs (unzipping)

Question 17

What enzyme ‘unzips’ the DNA?

Answer 17

DNA helicase

Question 18

What bonds does DNA helicase break?

Answer 18

Hydrogen bonds

Question 19

What happens to the DNA during replication after it has been unzipped?

Answer 19

Free DNA nucleotides bind to their complementary base of the template strand and hydrogen bonds form between A=T and C=G. The enzyme DNA polymerase joins the new nucleotides together by the formation of phosphodiester bonds, to produce a new sugar- phosphate backbone.

Question 20

What enzyme catalyses the condensation of the new nucleotides?

Answer 20

DNA polymerase

Question 21

Why does only one side of the unzipped DNA bond with nucleotides?

Answer 21

The DNA polymerase enzyme only works in one direction

Question 22

How does the direction of the strand effect the replication process? How is this overcome?

Answer 22

On one side the enzyme can travel the entire way (from 3’ to 5’). On the other strand the enzyme has to male small sections at a time and these sections have to be joined together by the enzyme DNA ligase

Question 23

What are the three types of RNA?

Answer 23

1. mRNA- messenger RNA
2. tRNA- transfer RNA
3. rRNA- Ribosomal RNA

Question 24

What is the structure of mRNA?

Answer 24

Messenger NA (mRNA) is a long single stranded molecules formed into a helix

Question 25

What is the structure of rRNA?

Answer 25

Ribosomal RNA (rRNA) is a long large, complex molecules made up of both double and single helices.

Question 26

What is the structure of tRNA?

Answer 26

Transfer RNA (tRNA) is a small single stranded molecule which forms a clover leaf shape. One end contains the bases CCA- this is where the acid attaches. At the opposite end of the molecule there is a series of 3 bases called the anticodon.

Question 27

What is the function of mRNA?

Answer 27

Manufactured in the nucleus and carries the genetic code from the DNA in the nucleus to the ribosome

Question 28

What is the function of rRNA?

Answer 28

Ribosomes are made up of rRNA and protein

Question 29

What is the function of tRNA?

Answer 29

tRNA molecules bring amino acids to the ribosome so that proteins can be synthesised.

Question 30

What are autotrophs?

Answer 30

Organisms that convert light energy from the sun to chemical energy to photosynthesis

Question 31

What are heterotrophs?

Answer 31

Organisms that cannot use the suns energy to make food

Question 32

What is the cells energy source?

Answer 32

ATP

Question 33

What does ATP stand for?

Answer 33

Adenine triphosphate

Question 34

What is ATP?

Answer 34

A nucleotide

Question 35

What is the structure of ATP?

Answer 35

Adenine bonded to a Ribose sugar bonded to 3 phosphate groups

Question 36

What does ADP stand for?

Answer 36

Adenine diphosphate

Question 37

What is the structure of ADP?

Answer 37

Adenine bonded to a Ribose sugar bonded to 2 phosphate groups

Question 38

Where is energy stored in the cell?

Answer 38

In the bonds of lipid and carbohydrate molecules

Question 39

What releases the energy stored in the bonds?

Answer 39

Breaking the bonds

Question 40

What enzyme catalyses the reaction of ATP to ADP?

Answer 40

ATPase

Question 41

How much energy does 1 mole of ATP release?

Answer 41

30.6 Kj

Question 42

What is Phosphorylation?

Answer 42

The addition of one inorganic phosphate group to ADP

Question 43

Why is ATP known as the universal energy currency of the cell?

Answer 43

This is because it is used by all living organisms, in every cell to carry energy from energy-releasing reactions to energy-consuming reactions. It is used to provide the energy for nearly all biochemical reactions in the cell.

Question 44

Why is glucose not a suitable energy source? (4)

Answer 44

1. Many enzymes are needed to release energy from glucose 2. The breakdown requires many intermediates so takes a long time 3. Glucose releases energy in large amounts, all at once 4. Large polar molecules

Question 45

Why is ATP a suitable energy source? (4)

Answer 45

1. ATP to ADP only requires the enzyme ATPase 2. ATP to ADP is a single step reaction so energy is released immediately 3. ATP released small amounts of energy at a time where its needed 4. Small, soluble molecules so easily transported

Question 46

What are the 5 roles of ATP?

Answer 46

1. Active Transport 2. Metabolic Processes 3. Movement 4. Nerve Transmission 5. Secretion