Bio unit 4

Question 1

photosynthesis

Answer 1

• uses energy to change reactants into products
• takes place in chloroplasts in green plant cells
• these contain pigments like chlorophyll that absorb light.
• endothermic reaction because energy is transferred to the chloroplast from the environment to the chloroplasts by light.

Question 2

Equation for photosynthesis

Answer 2

carbon dioxide +water——light—–> glucose +oxygen

Question 3

limiting factors(stop from happening faster) that affect rate of photosynthesis

Answer 3

• intensity of light(not enough light)
• concentration of CO2(not enough)
• temperature(too low or too hot bad, affect enzymes)
• amount chlorophyll, amount can be affected by disease or lack of nutrients. These damage chloroplasts to not make enough chlorophyll, cant absorb enough light, less photosynthesis.

Question 4

uses of glucose from photosynthesis

Answer 4

• used for respiration
• converted into insoluble starch for storage
• used to produce fat or oil for storage
• used to produce cellulose
• produce amino acids for protein synthesis.

Question 5

What do plants need to produce proteins?

Answer 5

nitrate ions that are absorbed from soil.

Question 6

what does respiration do?

Answer 6

-transfers the energy that the cell needs to carry out all living processes.

Question 7

what is respiration?

Answer 7

• processes of transferring energy from the breakdown of glucose, which goes on in every cell.
• exothermic reaction that continuously occurs in living cells.

Question 8

what are the two ways respiration in cells can take place as?

Answer 8

• aerobically (using oxygen)
• anaerobically (without oxygen)

Question 9

what do organisms need energy for?

Answer 9

• chemical reactions to build larger molecules
• movement(contracting muscles)
• keeping warm(keep constant body temp)

Question 10

what is anaerobic respiration in yeast cells called and its importance?

Answer 10

fermentation, economic importance because can be used to make bread and alcoholic drinks.

Question 11

what does the human body react to during exercise?

Answer 11

• increase in demand for energy because as you exercise your muscles contract and relax more.

Question 12

what happens during exercise to supply muscles with more oxygenated blood?

Answer 12

heart rate, breathing rate and breath volume increase

Question 13

what happens if theres an insufficient amount of oxygen supplied during exercise?

Answer 13

• anaerobic respiration takes place in muscles.
• incomplete oxidation of glucose causes a build up of lactic acid and creates an oxygen debt.
• during long periods of vigorous activity, muscles become fatigued and stop contracting efficiently.

Question 14

how is lactic acid converted back into glucose?

Answer 14

blood flowing through the muscles transports the lactic acid to the liver where it is converted back into glucose.

Question 15

oxygen debt

Answer 15

amount of extra oxygen the body needs after exercise to react with the accumulated lactic acid and remove it from the cells.

Question 16

metabolism

Answer 16

sum of all the reactions in a cell or the body

Question 17

How does respiration aid to the process of synthesizing new molecules?

Answer 17

Energy transferred by respiration in cells is used by the organism for the continual controlled processes of metabolism that synthesise new molecules.

Question 18

what does metabolism include?

Answer 18

• conversion of glucose to starch, glycogen and cellulose
• formation of lipid molecules from a molecule of glycerol and 3 molecules of fatty acids.
• respiration
• breakdown of excess proteins to form urea for excretion.
• use of glucose and nitrate ions to form amino acids which in turn are used to synthesise proteins.