6. Photosynthesis and Respiration

Question 1

What is Photosynthesis?

Answer 1

Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar. Glucose is used by plants for energy and to make other substances like cellulose and starch. Occurs in the chloroplasts which absorb energy from the sun convert this energy into usable energy for the plant.

Question 2

Anerobic respiration

Answer 2

Aerobic respiration occurs in the presence of oxygen, it is more efficient. Anerobic respiration occurs in the absence of oxygen = fermentation. In plants and yeast, glucose -> ethanol and carbon dioxide. In animals and some bacteral, glucose -> lactic acid.

Question 3

Cellular Respiration

Answer 3

Cellular respiration is a series of chemical reactions that break down glucose to produce ATP, which may be used as energy to power many reactions throughout the body.

Question 4

Autotrophs v Heterotrophs

Answer 4

Autotrophs are known are primary
producers because they are able to make their own food from raw materials and energy. Examples include plants, algae, and some types of bacteria. Heterotrophs are known as consumers because they consume producers or other consumers. Dogs, birds, fish, and humans are all examples of heterotrophs

Question 5

Homeostasis

Answer 5

Homeostasis is any self-regulating process by which an organism tends to maintain stability while adjusting to conditions that are best for its survival.

Question 6

Catabolic v Anabolic

Answer 6

Anabolic processes require energy to build large, complex molecules from small, simple molecules to help build and maintain muscle. Catabolic processes release energy as they break down large, complex molecules into small molecules, and break down muscle and fat (glycolysis)

Respiration is an anabolic process of releasing energy from simple sugar glucose for carrying out life. Photosynthesis is an anabolic process as plants use energy to convert carbon dioxide gas and water into sugar molecules.

Question 7

Factors that Affect Rate of Photosynthesis

Answer 7

• Light intensity
• CO2 Concentration
• Water availability
• Light colour
• Nutrients in soil
• Amount of Chloroplasts
• Size and orientation of leaf
• Type of leaf

Question 8

Formula for Photosynthesis and Respiration

Answer 8