B4 - The Processes of Life

Question 1

What is the symbol equation for Aerobic Respiration?

Answer 1

C₆H₁₂O₆ + 6O₂ –> 6CO₂+6H₂0+38ATP.

Question 2

What is the symbol equation for Anaerobic Respiration?

Answer 2

C₆H₁₂O₆ –> C₃H₆O₃ (Lactic acid) + 2ATP

Question 3

What is the symbol equation for photosynthesis?

Hint: It’s the opposite of Aerobic Respiration - minus the ATP!

Answer 3

6CO₂ + 6H₂O –> (Light energy/Chlorophyll) –> C₆H₁₂O₆ + 6O₂.

Question 4

What are some of the effects of lactic acid?

Answer 4

• Muscle aches.
• Cramp.
• Rapid breathing.
• Stomach pain.

Question 5

What organelles do both animal and plant cells have?

Answer 5

• Nucleus.
• Cytoplasm.
• Cell membrane.
• Mitochondria.
• Ribosomes.

Question 6

What additional organelles do plant cells have?

Answer 6

• Cell wall.
• Chloroplasts.
• Permanent vacuole.

Question 7

What is the job of the Nucleus?

Answer 7

The Nucleus holds genetic information, called DNA. Allows genetic transcription to take place.

Question 8

What is the job of the Cytoplasm?

Answer 8

The Cytoplasm is where chemical processes controlled by enzymes take place. This includes anaerobic respiration.

Question 9

What is the job of the Cell membrane?

Answer 9

The cell membrane controls the movement of substances in/out of a cell.

Question 10

What is the job of the Mitochondria?

Answer 10

The Mitochrondria is where most energy is released from respiration.

Question 11

What is the job of the Ribosomes?

Answer 11

The Ribosomes deal with Protein synthesis.

Question 12

What is the job of the Cell wall?

Answer 12

The Cell Wall strengthens the cell.

Question 13

What is the job of the Chloroplasts?

Answer 13

The Chloroplasts contain chlorophyll (A green pigment) which absorbs light energy for photosynthesis.

Question 14

What is the job of the Permanent vacuole?

Answer 14

The permanent vacuole is filled with cell sap to keep the cell enlarged with water. It is like a sack.

Question 15

How can Anaerobic Respiration be useful?

Answer 15

• It provides a little more energy to cells when very necessary, e.g: when running away from danger.
• In sewage farms, anaerobic microbes can be added to the solid matter. These break down the sewage and release methane gas, which is collected as a biogas.
• Anaerobic respiration is used in yeast when baking. Yeast in bread dough releases CO₂, which makes the dough rise before baking.
• Anaerobic respiration is also used in yeast for brewing to produce alcohol (ethanol). The process is known as fermentation. If oxygen gets in, the yeast stops respiring anaerobically, and the alcohol turns to vinegar (ethanoic acid).

Question 16

What is Diffusion?

Answer 16

The overall movement of substances from regions of high concentration, to regions of low concentration.

e.g: O₂, CO₂ and dissolved food.

Question 17

What is Active Transport?

Answer 17

The movement of substances from an area of low concentration to an area of high concentration.

REQUIRES ENERGY.

Question 18

What is Osmosis?

Answer 18

Osmosis is a type of diffusion, and is the movement of water from a high concentration to a low concentration.

Water passes through the cell membrane, which allows the passage of water molecules, but not solute molcules (They’re too big).

Question 19

Why is it important that the concentration of urea is kept very low?

Answer 19

Because it allows diffusion, keeps concentration gradient between blood and fluid and low concentration prevents urea moving from fluid back to blood.

Question 20

How do you irreversibly change the shape of the active site of an enzyme?

Answer 20

• Heating the enzyme above a certain temperature.
• Altering the pH level.

Question 21

What is cellulose?

Answer 21

A long polymer chain of glucose.

Question 22

What is starch?

Answer 22

A long chain of identical sugar molecules.

Question 23

How are proteins formed from glucose and nitrates?

Answer 23

1. The glucose and nitrates join together to make larger molecules of amino acids.
2. Amino acids are joined together to make proteins (Polymers of amino acids).

Question 24

How are proteins formed?

Answer 24

By creating amino acids through:

C₆H₁₂O₆ (Glucose) + NO_3- (Nitrate) –> Amino Acid (AA).

Proteins are polymers of Amino Acids.

Question 25

Explain how plants get their energy.

Answer 25

Plants need to absorb nitrates from the soil for healthy growth.

They normally absorb nutrients through diffusion, however the concentration of nitrates outside the plant is lower than that inside the plant, therefore the plant must use active transport to retain the nitrates.

The energy required for active transport comes from respiration.

Question 26

Explain how to conduct an experiment on how light affects plants.

Answer 26

Use a quadrat across a transect line and go up in intervals (e.g: 20 metres). Record the light intensity with a light meter at each result, and measure the number of different types of plants by eye and by using an identification key. Finally, see if there is a trend.

Note that using a quadrat is representive of the entire area but also random to avoid bias.