P1- Bioenergetics Flashcards
Word equation of photosynthesis
Carbon dioxide + Water —> Oxygen + Glucose
Define chlorophyll
Green pigment that is used to convert sunlight energy into chemical energy through the process of photosynthesis
What is an exothermic reaction?
When energy is transferred to the surroundings (feels hot)/ Releasing energy/heat
What is an endothermic reaction?
When energy is taken in from the surroundings (feels cold)/ Taking in energy/heat
How is the waxy cuticle adapted for photosynthesis?
Prevents water loss
How is the palisade mesophyll layer adapted for photosynthesis?
Contains lots of chloroplasts to maximise photosynthesis, has a large surface area to maximise light absorption
How is the spongy mesophyll adapted for photosynthesis?
Has gaps between cells to maximise gaseous exchange
How are the guard cells adapted for photosynthesis?
Open and close to help in gaseous exchange
What are some uses of glucose?
Respiration, storage as starch, storage as oils/fats, synthesis of cellulose for cell walls, produces amino acids for photosynthesis which requires nitrate ions from the soil
What are the limiting factors of photosynthesis?
Carbon dioxide concentration, light intensity, amount of chlorophyll, temperature
How is light a limiting factor of photosynthesis?
Increasing the light intensity increases the rate of photosynthesis, until some other factor (a
limiting factor) becomes in short supply.
How is carbon dioxide a limiting factor of photosynthesis?
Increasing concentration of CO2 can result in a faster photosynthesis up to a point where it then plateaus
How is temperature a limiting factor of photosynthesis?
Photosynthesis increases as temperature increases until the enzyme of each chemical reaction becomes denatured and photosynthesis stops/goes down
Define respiration
The process that releases energy from food, energy is not made but released, the energy transferred supplies all the energy
Why does our body need energy?
For movement, to keep warm and for chemical reactions to build larger molecules
Define aerobic respiration
Occurring in the presence of oxygen and in most cells most of the time
Word equation for aerobic respiration
Oxygen + Glucose —> Carbon dioxide + Water
What will happen if there is not enough oxygen available in aerobic respiration?
Anaerobic respiration
Define anaerobic respiration
Occurs without oxygen and much less frequently than aerobic respiration. Human muscles can respire anaerobically for short amounts of time
Where does anaerobic respiration occur?
Cytoplasm
Word equation for anaerobic respiration in animals and bacteria
Glucose —> Lactic acid (+Energy)
What does the build up of lactic acid in the muscles lead to?
Cramps
What will happen after respiring anaerobically over a longer period?
Muscles will fatigue and stop contracting
What is anaerobic respiration in plants and yeast also known as?
Fermentation
Word equation for anaerobic respiration in yeast and plants?
Glucose —> Ethanol (alcohol) + Carbon dioxide
Define oxygen debt
The amount of extra oxygen body needs after exercise to react with the accumulated lactic acid and remove it from the cells
Define lactic acid removal
Blood flowing through the muscles transports the lactic acid to the liver where it is converted back into carbon dioxide and water
Give examples of what happens to the body during exercise
Body temperature increases, heartbeat increases, low oxygen (change to anaerobic), breathing rate increases, feel tired, muscles feel fatigued, blood runs faster
Define metabolic rate
The speed at which chemical reactions take place in the body
Explain the body’s response to exercise
Body reacts to increased demand for energy, heart rate/breathing rate/breathe volume increases to supply muscles with more oxygenated blood, more aerobic respiration, more energy for expertise over time. If changes don’t occur, more anaerobic and less energy, lactic acid, muscles fatigue
What is protein broken down into
Amino acids
What are carbohydrates/starch broken down into
Sugars
What are lipids broken down into
Fatty acids and glycerol
Define metabolism
The sum of all of the reactions in a cell or the body
How does the heart link to respiration?
Pumps blood around the body
How does the blood link to respiration?
Carries reactants and products of respiration to and from cells
How does the lungs link to respiration?
Bring air containing oxygen into body and get rid of carbon dioxide
How does the mitochondria link to respiration?
Site of respiration in the cell
How do carbon dioxide and water link to respiration?
Waste products of respiration
How do glucose and oxygen link to respiration?
They are the reactants of respiration
