Bioenergetics

What is the balanced symbol equation for photosynthesis? (how much energy released too)

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ + 32ATP

Is photosynthesis endothermic or exothermic and why?

Endothermic, because it takes in light energy from the environment to react carbon dioxide and water.

What are the five main uses of glucose produced in photosynthesis?

1. Respiration 2. Converting to insoluble starch for storage 3. Producing fats/oils for storage 4. Producing cellulose for cell walls 5. Producing amino acids (combined with nitrate ions).

What are the three main limiting factors of photosynthesis?

Temperature, carbon dioxide concentration, and light intensity. (Chlorophyll levels can also be a factor).

Explain the 'Inverse Square Law' in relation to light intensity.

Light intensity is inversely proportional to the square of the distance from the source ($I \propto 1/d^2$)

How do commercial greenhouses maximize crop yield?

They control limiting factors by using heaters (temp), artificial lighting (light), and paraffin heaters (which release $CO_2$).

What is the balanced symbol equation for aerobic respiration? (how much energy)

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 32 ATP

Is respiration endothermic or exothermic and why?

Exothermic, because it releases energy to the environment when chemical bonds in glucose are broken.

Why do organisms need energy from respiration?

For chemical reactions (building molecules), movement (muscle contraction), and keeping warm (in mammals/birds).

What is the word equation for anaerobic respiration in muscles? (how much energy released)

Glucose → Lactic acid + 2ATP

Why is anaerobic respiration less efficient than aerobic?

The oxidation of glucose is incomplete, so much less energy is released.

What is the word equation for anaerobic respiration in plant and yeast cells?

Glucose → Ethanol + Carbon dioxide.

What is anaerobic respiration in yeast called and what are its uses?

Fermentation

What three things happen to the body during exercise to supply more oxygen?

Heart rate increases, breathing rate increases, and breath volume increases.

What is 'Oxygen Debt'?

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

How is lactic acid removed from the body?

Blood flows through the muscles to transport lactic acid to the liver, where it is converted back into glucose.

What is 'Muscle Fatigue'?

A condition caused by long periods of vigorous activity where muscles stop contracting efficiently.

Define metabolism.

The sum of all the reactions in a cell or the body.

List three examples of metabolic reactions.

1. Conversion of glucose to starch/glycogen/cellulose 2. Formation of lipids from glycerol and fatty acids 3. Breakdown of excess proteins to form urea.

What is the role of the liver in metabolism?

It filters the blood, breaks down old red blood cells, and converts lactic acid back into glucose/glycogen.