ATP/light dep/indep rcn./photosynthesis.

What is dehydrogenation?

the removal of hydrogen from a molecule.

"Describe the light dependent reaction."

1 Light (energy) excites/raises energy level of electrons in chlorophyll; 2 Electrons pass down electron transfer chain; 3 passage involves redox reactions; 5 Energy released / carriers at decreasing energy levels; 6 ATP generated from ADP and inorganic phosphate.

Humans synthesise more than their body mass of ATP each day. Explain why it is necessary for them to synthesise such a large amount of ATP.

1. ATP is unstable; 2. ATP cannot be stored / is an immediate source of energy; 3. Named process uses ATP ; 4. ATP only releases a small amount of energy at a time;

"During photosynthesis, oil-palm trees convert carbon dioxide into organic substances. Describe how."

1. Carbon dioxide combines with ribulose bisphosphate/RuBP this Produces two molecules of glycerate (3-)phosphate/GP; 2. the GP is then Reduced to triose phosphate/TP; 2.ATP and REDUCED NADP are required for the reduction of GP to triose phosphate. 6. Triose phosphate converted to other organic substances e.g. glucose. 7. In the light independent reaction/Calvin cycle;

"In the light-independent reaction of photosynthesis, the carbon in carbon dioxide becomes carbon in triose phosphate. Describe how."

1. Carbon dioxide combines with ribulose bisphosphate/RuBP; 2. To produce two molecules of glycerate 3-phosphate/GP; 3. the GP is then Reduced to triose phosphate/TP; 4.ATP and REDUCED NADP are required for the reduction of GP to triose phosphate.

Give two ways in which the properties of ATP make it a suitable source of energy in biological processes.

1. Energy released in small/suitable amounts; 2. Soluble; 3. Involves a single/simple reaction;

Optimum conditions for photosynthesis?

1. High light intensity of a certain wavelength. 2.Optimum temperature (usually 25c). (if temp is too low, enzymes become inactive, if temp is too high, enzymes denature- at high temps, stomata close to avoid losing too much water, so photosynthesis slows down as less CO2 enters leaf when stomata are closed). 3. Carbon dioxide at 0.4%

"Plants produce ATP in their chloroplasts during photosynthesis. They also produce ATP during respiration. Explain why it is important for plants to produce ATP during respiration in addition to during photosynthesis."

1. In the dark there is no ATP production in photosynthesis. 2. Some tissues may be unable to photosynthesise and produce ATP. 3. ATP cannot be stored. 4. Plant uses more ATP than they produce, in photosynthesis; 5. ATP is needed for active transport.

DNP inhibits respiration by preventing a proton gradient being maintained across membranes. When DNP was added to isolated mitochondria the following changes were observed 1. less ATP was produced 2.more heat was produced 3. the uptake of oxygen remained constant. Explain how DNP caused these changes.

1. Less H+ movement so less ATP produced; 2. Heat released from electron transport. 3. Oxygen used as final electron acceptor.

"The student CLOSED the tap. After thirty minutes the drop of coloured liquid had moved to the left. Explain why the drop of coloured liquid moved to the left."

1. Oxygen taken up/used (by woodlouse); 2. Carbon dioxide (given out) is absorbed by solution/potassium hydroxide; 3. Decrease/change in pressure;

"ATP is useful in many biological processes. Explain why."

1. Releases energy in small / manageable amounts. 2. It is broken down in one step 3. It's an immediate energy compound. 4. Phosphorylates substances and makes them more reactive/ lowers activation energy; 6. It can be reformed.

What enzyme catalyses the reaction?

ATP synthase.

When ATP diffuses to the part of the cell where it is needed, it is broken down into ADP and inorganic phosphate. What enzyme catalyses this reaction?

ATPase.

What is phosphorylation?

Adding phosphate to a molecule

What is photophosphorylation?

Adding phosphate to a molecule using light energy.

Thylakoids () are stacked up in the chloroplast intro structures called...

GRANA. (singular = granum)

Why do humans need energy?

Humans need energy for biological processes such as muscle contraction, maintaining body temperature, active transport, DNA replication, sell division and finally protein synthesis.

What do NAD and FAD do?

NAD and FAD transfer hydrogen from one molecule to another. Meaning they can reduce (when you give hydrogen) or oxidise (when you take hydrogen) a molecule.

What are some examples of coenzymes used in respiration?

NAD, coemzyme A amd FAD.

Why do plants need energy?

Plants need energy for biological processes such as photosyntehsis, active transport, DNA replication, cell division and protein synthesis.

What measurement should the student take to calculate the rate of aerobic respiration in mm3 of oxygen g-1 h-1?

The diameter of the capillary tubing. The distance the drop moves and time. The mass of the woodlouse.

What is decarboxylation?

The removal of carbon dioxide from a molecule.

What is ATP synthesised from?

from ADP and inorganic phosphate.

Where does the light INdependent reaction take place?

in the stroma of the chloroplast.

What does coenzyme A do?

it transfers acetate between molecules.

Where does the light dependent reaction take place?

thylakoid membranes.