ATP

Question 1

Describe the properties of water and explain how each property is biologically important

Answer 1

Metabolite- hydrolysis and condensation reactions
Solvent- allows reactions to occur in cells and for transport of substance
High specific heat capacity- buffers changes in body temperature
Large latent heat of vapourisation- provides a cooling effect with little loss of water through evaportion
Cohension- between water molecules due to hydorgen bonding supports columns of water during the transport of water through the xylem of plants and produces surface tension to support small organisms

Question 2

List the biological role for the inorganic ion, Fe2+

Answer 2

found in haemoglobin in red blood cells. O2 binds to the Fe2+ and transports the oxygen to respiring cells.
Haemoglobin has a quaternary structure with 4 polypeptide chains, each with 1 Fe2+, so each haemoglobin can carry 4 O2 molecules.

Question 3

Describe the structure of ATP

Answer 3

Adenosine triphosphate contains ribose sugar, adenine and 3 phosphate groups

Question 4

List the biological roles of the inorganic ion, H+

Answer 4

Higher concentration of H+ ions, lowers the pH
High/low concentration of H+ ions can denature proteins including enzymes and so affect rates
H+ ions are used in photosynthesis and respiration along with ATP synthase, for the formation of ATP from ADP and Pi.

Question 5

List the biological importance of the inorganic ion, Na+

Answer 5

involved in the adsorption of glucose into bloodstream.
Co-transported along with glucose into the epithelial cells of the small intestine down a Na+ concentration gradient.
Involved with the production of electrical impulses in neurones.
Water reabsorption in the kidneys

Question 6

List the biological importance of the inorganic ion, PO43+

Answer 6

PO43+ added to ADP to produce ATP in a condensation reaction during photosynthesis and respiration.
added to other molecules to make them more reactive (phosphorylation)
used to join DNA and RNA nucleotides together via phosphodiester bonds in the sugar-phosphate backbone.
Makes up the hydrophilic part of the phospholipid bilayer

Question 7

Explain how hydrogen bonds form between molecules

Answer 7

Due to their polar nature, weak hydrogen bonds are produced between the slightly negative oxygen is attracted to the slightly positive hydrogen, in water.

Question 8

Name 3 differences between a ATP and DNA nucleotide

Answer 8

1. ATP has a ribose sugar, whereas DNA has a deoxyribose sugar.
2. ATP has 3 phosphates but DNA only has 1.
3. ATP always has adenine as the base but DNA can have adenine, guanine, thymine or cytosine.

Question 9

Name 3 biological processes that use the energy from the hydrolysis of ATP

Answer 9

1. Active transport
2. Muscle contraction
3. Synthesising molecules
4. Mitosis

Question 10

Write the equation for the synthesis of ATP

Answer 10

ADP + Pi > ATP + water
(Using ATP synthase)

Question 11

Write the equation for the hydrolysis of ATP

Answer 11

ATP + water > ADP + Pi
(Using ATP hydrolase)

Question 12

Name the enzyme used to hydrolyse ATP

Answer 12

ATP hydrolase

Question 13

Name the enzyme used to synthase ATP

Answer 13

ATP synthase