Bioenergetics

Question 1

Word equation for photosynthesis

Answer 1

Carbon dioxide + Water –> Glucose and Oxygen

Question 2

Balanced equations of photosynthesis

Answer 2

6Co2 + 6H20 –> C6H12O6 + 6O2

Question 3

Where does the energy from photosynthesis come from

Answer 3

Comes form light energy(sunlight)

Question 4

How does temperature affect the rate of photosynthesis

Answer 4

At low temperature the molecules do not have enough kinetic energy to react together fast enough. At too high temperature, the enzymes that control the photosynthesis reaction(active site changes shape).Therefore the rate of photosynthesis decreases.

Question 5

How does light intensity affect the rate of phtotsynthesis

Answer 5

As the light intensity increases, more light is available for photosynthesis. Once light intensity reaches a certain level, the rate of photosynthesis becomes constant as another factor must be limiting the process of photosynthesis

Question 6

How does chlorophyll affects the rate of photosynthesiss

Answer 6

If a plant has more chloroplasts, more light can be absorbed for photosynthesis but at a certain level another factor must be limiting the process of photosynthesis

Question 7

How does carbon dioxide concentration affect the rate of photosynthesis

Answer 7

As carbon dioxide concentration increases, more light is available for photosynthesis. Once carbon dioxide concentration reaches a certain level, the rate of photosynthesis becomes constant as another factor must be limiting the process of photosynthesis

Question 8

Inverse square law

Answer 8

1/d squared

Question 9

Explain how limiting factors are important in the economics of enhancing the conditions of a greenhouse to gain the maximum rate of photosynthesis while still maintaining profit

Answer 9

Light Intensity - Without enough light a plant cannot photosynthesise very fast, even if there is plenty of water and carbon dioxide. Increasing the light intensity will make photosynthesis faster.
Carbon dioxide level - Photosynthesis can be limited by the level of carbon dioxide. Even if there is plenty of light a plant cannot photosynthesise if it has run out of carbon dioxide.
Temperature - If it gets too cold the rate of photosynthesis will slow right down. If it gets too hot then plants cease to be able to photosynthesise.

Question 10

Six uses of glucose in plants

Answer 10

• Used for respiration
• Can be stored as insoluble starch
• Can be used to make fats and oils
• Used to make cellulose that strengthens the cell wall
• Used to make amino acids which are the building blocks of cells
• Can combine with nitrates to form amino acids and proteins for growth and repair

Question 11

How do plants use nitrates that are absorbed from the soil

Answer 11

Plants use nitrates. as a supply of nitrogen, which is needed to make proteins for healthy growth. Plants absorb nitrates in water through their roots. Nitrates are present in high levels in plant fertilisers.

Question 12

Differences of aerobic and anaerobic respiration

Answer 12

• Aerobic respiration needs oxygen however anaerobic does not
• Aerobic respiration releases more oxygen but more slowly but anaerobic releases less energy but more quickly
• The products of aerobic respiration are carbon dioxide and water and atp but anaerobic is lactic acid

Question 13

What is aerobic respiratio

Answer 13

the release of a relatively large amount of energy in cells by the breakdown of food substances in the presence of oxygen

Question 14

What us anaerobic respiration

Answer 14

Respiration without oxygen

Question 15

Balanced symbol equation for aerobic resporation

Answer 15

C6H12O6+6O2==>6CO2+6H20

Question 16

Word equation for anaerobic in muscles

Answer 16

Glucose equals lactic acid

Question 17

Equation for anaerobic in yeast cells and plant

Answer 17

Glucose makes ethanol and carbon dioxide

Question 18

Why does anaerobic respiration take place in muscles

Answer 18

During vigorous exercise your body cells may not have enough oxygen for aerobic respiration to take place and anaerobic respiration occurs instead. Anaerobic respiration releases less energy than aerobic respiration but it does this more quickly. The product of this reaction is lactic acid.

Question 19

What is muscle fatigue and oxygen debt

Answer 19

Muscle use can quickly overwhelm the ability of the body to deliver oxygen. Muscle fibers must switch to anaerobic metabolism and produce lactic acid, at which point the muscle begins to fatigue. The difference between the amount of oxygen needed by the muscles and the actual amount present is called the oxygen debt.

Question 20

Function of liver in the removal of lactic acid

Answer 20

The blood flow through muscles removes lactic acid and transports it to the liver. In the liver, the lactic acid is converted back into glucose. This reaction requires energy, hence the extra need for oxygen

Question 21

Define metabolism

Answer 21

The sum of al the reactions that take place in a cell or in a body

Question 22

6 metabolic reactions

Answer 22

1- conversion of glucose to starch glycogen or cellulose
2- the formation of lipid molecules from a molecule of glycerol and three fatty acid molecules
3- the use of glucose and nitrate ions to form amino acids that are then used to make proetins
4- reactions for respiration
5- reactions of photosynthesis
6- the breakdown of excess protein in the liver to form urea for excretion in the urine by the kidneys