Ocr Biology F214 Respiration And Photosynthesis

Front 1

Describe the structure of ATP.

Back 1

One Adenosine molecule, one Ribose sugar and three Phosphate groups.

Front 2

Why is ATP a good source of energy?

Back 2

It releases small, manageable amounts so none is wasted. It soluble and easily transported. It is easily broken down and easily stored.

Front 3

What are coenzymes?

Back 3

Molecules that aid the function of an enzyme by transferring a chemical group.

Front 4

How are mitochondria adapted to their function?

Back 4

The inner membrane is folded into Cristae providing a large surface area, there are lots of ATP synthase molecules in the membrane, the matrix contains all the enzymes and reactants needed.

Front 5

Where does Glycolysis take place?

Back 5

The cytoplasm

Front 6

Where does the Link reaction take place?

Back 6

The mitochondrial Matrix

Front 7

Where does the Krebs cycle take place?

Back 7

The mitochondrial matrix.

Front 8

Where does Oxidative Phosphorylation take place?

Back 8

The inner membrane of the mitochondria.

Front 9

Describe what occurs during Glycolysis.

Back 9

Glucose is phosphorlyated to Hexose Bisphosphate using 2 ATP. This splits into 2x triose phosphate which is phosphorlyated and oxidised to 2x Pyruvate.

Front 10

Describe what occurs during the link reaction.

Back 10

Pyruvate is decarboxylated and oxidised to actetate. Coenzyme A is added producing Acetyl Coenzyme A.

Front 11

Describe what occurs during the Krebs cycle.

Back 11

Acetyl CoA combines with Oxaloacetate to form citrate which is decarboxylated and oxidised to produce a 5 carbon compound. Dcarboxylation, 3 oxidation (with NAD and FAD) and phosphorylation occurs to regenerate Oxaloacetate.

Front 12

Describe what occurs during Oxidative Phosphorylation.

Back 12

Electrons move along the electron transport chain losing energy, the energy is used to actively pump hydrogen ions into the intermembrane space creating an electrochemical gradient, protons move down the gradient through ATP synthase driving ATP synthesis. Oxygen is the final electron acceptor.

Front 13

Why is the actual yield of ATP lower than the expected yield?

Back 13

Some reduced NAD is used in other reduction reactions, some ATP is used in actively transporting substances into the mitochondria ans the inner membrane is leaky.

Front 14

How can a respirometer be used to measure respiration rate?

Back 14

A syringe sets the fluid in the manometer to a known level and it is left for a set period of time. There will be a decrease in the volume of air reducing the pressure which will cause the liquid to move towards the test tube. The distance moved is recorded. KOH removes Carbon dioxide.

Front 15

Describe the process of Lactate fermentation.

Back 15

Pyruvate is reduced to lactate using NAD which is used in glycolysis.

Front 16

Describe the process of Alcoholic fermentation.

Back 16

Pyruvate is decarboxylated to ethanal which is reduced to ethanol using NAD which is then used in glycolysis.

Front 17

Why is the ATP yield of Anaerobic respiration lower than that of Aerobic respiration?

Back 17

Only one energy releasing stage is involved, as the krebs cycle and Oxidative Phosphorylation require Oxygen.

Front 18

What is the Respiratory Substrate?

Back 18

The type of substrate being respired.

Front 19

What is the Respiratory quotient of Lipids, Carbohydrates and Proteins?

Back 19

Lipids= 0.7

Carbohydrates= 0.9

Proteins=1

The higher the quotient the greater the shortage of Oxygen.

Front 20

How can the respiratory quotient be calculated?

Back 20

Volume of Carbon Dioxide released over volume of oxygen consumed.

Front 21

What is an autotroph?

Back 21

An organism that uses light/chemical energy and inorganic molecules to produce complex organic molecules.

Front 22

What is a Heterotroph?

Back 22

An organism that ingests and digests complex organic molecules, releasing the chemical potential energy stored in them.

Front 23

How are chloroplasts adapted to their function?

Back 23

Grana provide large surface area, the stroma contains all the reactants and enzymes needed.

Front 24

What are Photosynthetic pigments?

Back 24

Molecules that absorb light energy. They absorb a range of wavelengths and they all have their own peak of absorption.

Front 25

What are Primary Pigments?

Back 25

The reaction centre, there are two forms of cholorphyll a- p680(Photosystem 2) and p700(photosystem1). Chlorophyll a absorbs wavelengths of 450nm and chlorophyll b absorbs wavelengths of 500nm and 640nm.

Front 26

What are accessory pigments?

Back 26

Not directly involved in the reaction, they absorb wavelengths not well absorbed by chlorophyll.

eg. Carotene and Xanthophyll.

Front 27

Describe Non-Cyclic phosphorylation.

Back 27

Light energy absorbed by PSII excites electrons causing them to move to a higher energy level along the ETC. The energy lost is used to pump protons into the thylakoid. Protons move down the gradient through ATP synthase driving ATP synthesis. Light energy is absorbed by PSI transferring electrons to NADP. (electrons fomr water)

Front 28

Describe Cyclic Phosphorylation.

Back 28

The same process but it only involves PSI and only produces ATP.

Front 29

Describe the Light independent reaction.

Back 29

Carbon dioxide is added to Ribulose Bisphosphate using Rubisco to produce 2 mols of Glycerate phosphate. This is phosphorylated and oxidised to produce triose phosphate. ATP is required to regenerate ribulose bisphosphate.

Front 30

What are the uses of triose phosphate?

Back 30

To produce Carbohydrates (hexose sugars) and glycerol.

Front 31

What are the uses of Glycerate phosphate?

Back 31

To produce fatty acids and amino acids.

Front 32

How many cycles does it take to produce a hexose sugar?

Back 32

Six because five out of six molecules of triose phosphate are used to regenerate Ribulose Bisphophate.

Front 33

What are the optimum conditions for photosynthesis?

Back 33

Red and blue light

25 degrees

0.4% Carbon dioxide

Front 34

What is the saturation point?

Back 34

When increasing a factor has no further effect because something else has becoming the limiting factor.

Front 35

Why does light intensity affect photosynthesis?

Back 35

Slows down light dependent reaction so conversion of GP to TP and RuBP are slow due to lack of ATP and reduced NADP.

Front 36

Why does temperature affect photosynthesis?

Back 36

Affects enzyme activity so levels of RuBP, GP and TP will fall.

Front 37

Why does carbon dioxide concentration affect photosynthesis?

Back 37

Carbon dioxide is required to produce GP so levels of RuBP will rise but levels of TP and GP will fall.