Bioenergetics

Question 1

Photosynthesis Equation

Answer 1

carbon dioxide + water ——–> (light/chlorophyll) glucose + oxygen

Question 2

Balanced Equation

Answer 2

6CO,2 + 6H,2,O -> C,6,H,12,O,6 + 6O,2

Question 3

Carbon DIoxide

Answer 3

Taken in through stomata = gas exchange (diffusion)

Question 4

Water

Answer 4

Osmosis from soil - move upstream by transpiration by xylem vessels.

Question 5

Glucose

Answer 5

Transported by phloem cells (translocation) - some used in respiration -

Stored as a starch - insoluble storage substance made from chain of glucose molecules so that when the plant cannot carry out photosynthesis it can break down the starch into glucose and use it up to survive.

Cellulose - Needed for structural support in plant cells - cell wall.

Amino Acids - For protein synthesis - also need nitrate ions from the soil to do this.

Produce fat or oil (lipids) for storage.

Question 6

Oxygen

Answer 6

Exchanged with CO,2 - released through stomata.

Question 7

Endothermic Chemical Reactions

Answer 7

Energy is taken from the surrounding

Question 8

Uses of glucose

Answer 8

1) Starch: insoluble and made of glucose molecules so that when plants cannot carry out photosynthesis it can break down the starch into soluble glucose and use it up.
2) In respiration
3) Cellulose for cell walls
4) Produce fat or oil (lipids) for storage or energy
5) Amino acids with nitrate ions from soil for protein synthesis

Question 9

Limiting factors of photosynthesis

Answer 9

• Carbon Dioxide: reactant, so increasing concentration increases the rate of photosynthesis.
• Light Intensity: increasing light intensity increases the rate of photosynthesis.
• Temperature: at low temperatures the rate of photosynthesis is slow since the reactant molecues have less kinetic energy.
  However, if the temperature is too high, the enzymes are quickly de-natured and the process rate decreases.

Question 10

Inverse Square Law

Answer 10

1/distance^2

Question 11

Exothermic Chemical Reaction

Answer 11

Releases Energy

Question 12

Aerobic Respiration Word Equation

Answer 12

glucose + oxygen -> carbon dioxide + water

Question 13

Aerobic Respiration Symbol Equation

Answer 13

C6H12O6 + 6O2 -> 6CO2 + 6H2O

Question 14

Aerobic Respiration

Answer 14

Requires Oxygen - complete oxidation of glucose - large amount of energy is released.

Question 15

Anaerobic Respiration

Answer 15

Incomplete oxidation of glucose so much less energy is released

Question 16

Anaerobic Respiration Equation

Answer 16

glucose -> lactic acid

Question 17

Fermentation

Answer 17

Anaerobic respiration in yeast cells:
glucose -> ethanol + carbon dioxide

Also known as alchoholic fermentation: important in the manufacturing ofbread and alchoholic drinks.

Question 18

Anaerobic Respiration as a response to excercise

Answer 18

If insufficient oxygen is supplied, anaerobic respiration takes place leading to a build up of lactic acid -> muscles become fatigued and sore and then stop contracting efficiently.

Question 19

What happens after anaerobic respiration in muscles:

Answer 19

After exercise, the lactic acid accumulated needs to be removed. The amount of oxygen needed to react with the lactic acid to remove it from the cells is referred to as ‘OXYGEN DEBT’

Question 20

How is lactic acid removed?

Answer 20

lactic acid in muscles -> transported to the liver in the blood -> lactic acid is converted back to glucose

Question 21

Metabolism Definition

Answer 21

Sum of all the reactions in a cell or the body, in which new molecules are made or broken down.

Question 22

Metabolic Products

Answer 22

1. Glucose -> builds to glycogen or starch or cellulose
2. Making Lipids (fatty acids)
3. Making proteins
4. Respiration
5. Amino Acids

Question 23

Metabollic processes include the synthesis and breakdown of:

Answer 23

CARBOHYDRATES
- Glucose to starch, glucose or cellulose
- Breakdown of glucose to use in respiration

PROTEINS
- Amino acids from glucose + nitrate ions
- Amino acids to protein
- Excess proteins broken down to form urea for excretion

LIPIDS