B4- BIOENERGETICS Flashcards
What is the EQUATION for photosynthesis?
Water + Carbon Dioxide -> Glucose + Oxygen
6H20 + 6CO2 -> C6H12O6 + 6O2
What type of reaction is photosynthesis?
Endothermic (Energy is needed)
What is GLUCOSE used for?
-Respiration
-Glucose can be turned into starch or fat to store energy
-Making cellulose (cell walls)
-Making amino acids for synthesising proteins.
How can the RATE OF PHOTOSYNTHESIS be increased?
-Increasing temperature
-Increasing light intensity
-Increasing CO2 concentration
THESE CAN ALSO BE LIMITING FACTORS.
Describe the PRATICAL INVESTIGATING PHOTOSYNTHESIS
1) Prepare a boiling tube containing sodium hydrogen carbonate. Shake to disperse any formed air bubbles.
2) Cut pondweed stem and use forceps to place pondweed in boiling tube.
3) Position boiling tube so that the pondweed is 10cm away from light source ; allow time to acclimatise.
4) Count number of bubbles emerged from the cut end of the stem in a minute.
OR use a gas syringe to collect the volume of gas produced.
5) Repeat count 5 times and record results. Then calculate an average number of bubbles produced / minute.
6) Repeat experiment at different distances from the light source.
PRACTICAL INVESTIGATING PHOTOSYNTHESIS ; VARIABLES
Independent variable; distance from light source
Dependant variable ; number of bubbles / minute
Control; concentration of solution OR temperature OR pondweed used.
What law does the practical investigating photosynthesis follow?
INVERSE SQUARE LAW ;
Distance x2 = Light intensity / 4
What does RESPIRATION provide energy for?
-Chemical reactions
-Warmth
-Movement
What is the EQUATION for AEROBIC RESPIRATION?
glucose + oxygen -> water + carbon dioxide
C6H12O6 + 6O2 -> 6H2O + 6CO2
What is the EQUATION for ANAEROBIC RESPIRATION?
glucose -> lactic acid
When does ANAEROBIC RESPIRATION take place?
Occurs during intense exercise; results in oxygen debt - more oxygen is needed afterwards to break down LACTIC ACID into glucose in the liver.
What is the EQUATION for ANAEROBIC RESPIRATION in PLANTS?
glucose -> ethanol + carbon dioxide
ALSO KNOWN AS FERMENTATION.
What is METABOLISM?
The sum of all chemical reactions in a cell/organism.
e.g, glucose -> starch, cellulose and glycogen
fatty acids -> lipids
respiration
breakdown of excess proteins -> urea
What happens during EXERCISE?
Heart and breathing rate increase to supply more oxygen and glucose to enable muscles to contract.
