B4 - Bioenergetics

Question 1

PHOTOSYNTHESIS

Answer 1

Water + Carbon Dioxide → Glucose + Oxygen
6H2O + 6CO2 → C6H12O6 + 6O2

Sunlight Needed For Photosynthesis so It is a Endothermic Reaction

Question 2

GLUCOSE MADE FROM PHOTOSYNTHESIS IS USED FOR

Answer 2

Respiration
Making Starch/Fat to Store Energy
Making Cellulose
Making Amino Acids for Proteins

Question 3

RATE OF PHOTOSYNTHESIS IS INCREASED BY

Answer 3

Increasing Temperature

Increasing Light Intensity

Increasing CO2 Concentration

Question 4

PHOTOSYNTHESIS PRACTICAL - INDEPENDENT/DEPENDENT VARIABLE

Answer 4

Independent Variable :
Distance between Plant and Light Source
Dependent Variable :
Rate of Photosynthesis (Indicated by Oxygen Produced)

Question 5

PHOTOSYNTHESIS PRACTICAL

Answer 5

1. Put Pond Weed in a Test Tube or a Measuring Cylinder
2. Add Sodium Hydrogen Carbonate, then Cut Stem at an Angle ( While Submerged )
3. Invert and put in Beaker, Ensuring there is No Air at the Top
4. Carry Out Investigation in a Dark Room
5. Position Light Source at a Distance Measured with a Metre Ruler
6. Wait 1 minute for the Plant Acclimatise to the Light Intensity
7. Start Stop clock and Count how many Bubbles produced in 1 minute
   8.Change the Distance and Repeat

Question 6

What RELATIONSHIP does LIGHT INTENSITY follow ?

Answer 6

Light Intensity follows an Inverse Square Relationship with Distance

eg. If the Distance is x2, the Intensity is
/4, as should the Rate of Photosynthesis ( Provided Light Intensity is the Limiting Factor )

Question 7

What does RESPIRATION PROVIDE ? and What for ?

Answer 7

Energy.
It Provides Energy for Chemical Reactions, Warmth and Movement

Question 8

What is the Equation for AEROBIC RESPIRATION ( WITH OXYGEN ) ?

Answer 8

Glucose + Oxygen → Water + Carbon Dioxide

Question 9

What happens to HEART RATE and BREATHING RATE DURING EXERCISE and What does this LEAD to?

Answer 9

Heart and Breathing Rate Increase to Increase Blood Flow to Supply More Oxygen and Glucose to Enable Muscles to Contract

Question 10

ANAEROBIC RESPIRATION ( WITHOUT OXYGEN )
- What is the EQUATION ?
- When does it OCCUR ?
- What is BROKEN DOWN ?

Answer 10

Glucose → Lactic Acid

Occurs during Intense Exercise ; Oxygen Debt

Lactic Acid is Broken back down into Glucose by the Liver using Oxygen

Question 11

ANAEROBIC RESPIRATION IN PLANTS

Answer 11

Glucose → Ethanol + Carbon Dioxide

Fermentation

Question 12

What is METABOLISM?

Answer 12

The Sum of All Chemical Reactions in a Cell/Organism

eg. Glucose → Starch, Glycogen and Cellulose
Fatty Acids → Lipids ( Fats )
Respiration
Breakdown of Excess Proteins → Urea