cellular respiration and photosynthesis Flashcards
(24 cards)
autotrophs
Organisms that use light energy from the sun to produce food Ex: plants and some microorganisms (some bacteria and protists
heterotrophs
Organisms that CANNOT use the sun’s energy to make food Ex: animals and most microorganisms
without energy cells would not be able to
grow, repair, reproduce, synthesize proteins, fats and carry out their daily activities.
ATP
Cells usable source of energy
ATP stands for adenosine triphosphate.
It is a chemical molecule which is stored in cells
where is high amount of energy stored?
ATP has a high amount of ENERGY stored in the last phosphate bond.
When the cell needs energy for its activities, the last phosphate bond is broken to release the energy required.
where is low amount of energy
Once the energy is released, the molecule left from ATP is called ADP (adenosine diphosphate) which is a low energy molecule.
what is the purpose of cellular respiration?
Cellular respiration is the process by which the energy of glucose is released in the cell and converted to ATP to be used for life processes (movement, breathing, blood circulation, etc…)
aerobic respiration
requires oxygen
Occurs in the cytosol & mitochondria of the cell
Total of 30 or 32 molecules produced from each glucose molecule.
aerobic respiration worded equation
glucose + oxygen —-> carbon dioxide + water + ATP
glycolysis
occurs in the cytosol where glucose is split into two pyruvate molecules
2ATP & NADH generated
krebs cycle
- occurs inside the mitochondrial matrix
pyruvate is broken down in a series of reactions and CO2 is released - 2ATP generated
More carriers are loaded with H+
( NADH and FADH2)
electron transport chain
occurs on the cristae of mitochondria (inner membrane)
uses O2 to produce water
loaded H+ carriers deliver and release their H+ ions
26 or 28 ATP generated.
Alcoholic fermentation
occurs in bacteria and yeast , glucose is convereted into pyruvate with the release of atp then further convereted into final products of alcohol and carbon dioxide
Glucose ——> alcohol + carbon dioxide + 2 ATP
lactic acid fermentation
occurs in animal cells ( eg muscle cells)
Lactic acid is produced in the muscles during rapid exercise when the body cannot supply enough oxygen to the tissues—causes burning sensation in muscles
glucose ——-> lactic acid + 2 ATP
Explain why anaerobic respiration does not make as much ATP as aerobic respiration.
as it doesnt involve oxygen
factors that affcet the rate of respiration
- temp
As temp increases towards the optimum range, the rate of cellular respiration increases.
At the optimum temperature, cellular respiration will occur at the maximum rate.
At the temperatures above the optimum temperature, the rate of cellular respiration rapidly decreases as enzymes (controlling the rate of respiration) are denatured (lose their shape and function) - glucose avaliability
Increasing the amount of glucose will increase the rate of respiration until a saturation point is reached.
A maximum rate is reached when the enzymes within the cells are operating at their maximum capacity. - oxygen concentration
Increasing the concentration of oxygen will increase the rate of aerobic respiration until it reaches a max rate (as enzymes are limited – even if more oxygen is available)
What is the purpose of photosynthesis and what type of cells carry it out?
Photosynthesis is the process by which the energy of sunlight is converted into the energy of glucose.
This is carried out by plants and other autotrophs.
Where does photosynthesis occur and when?
Photosynthesis occurs in the chloroplasts of mesophyll cells found in the leaves of plants. This reaction takes place during the daytime, when sunlight is present
worded and a balanced chemical equation for photosynthesis
carbon dioxide + water ——-> glucose + oxygen
6CO2 + 6H2O ——-> C6H12O6 + 6O2
chloraplasts
Chloroplasts are double membraned organelles.
Liquid filling inside is called the STROMA.
Inner membrane has stacks called GRANA (stacks of thykaloid disks) which are filled with chlorophyll – the green light absorbing pigment
Red and blue light are absorbed by chlorophyll.
Green light is reflected.
Light Dependent Reaction
Occurs in the grana (thylakoid membrane)
lihgt is abosrbed by chloraphyll in grana
H2O is split by light energy to produce energy carriers, ATP and NADPH (electron carrier). O2 is released.
calvin cycle
Occurs in the stroma of the chloroplast.
energy is transferred from ATP and NADPH(provided from the light dependent reaction) to carbon dioxide to make glucose.
Factors affecting the rate of photosynthesis
Temperature: Photosynthesis increases with temperature up to an optimal point, but too much heat can damage enzymes and slow the process.
Carbon dioxide concentration: More CO₂ increases the rate of photosynthesis up to a certain level, as it’s a key reactant.
Light intensity: Higher light intensity boosts the rate, but only up to a saturation point.
Water availability: Water is essential for photosynthesis; a shortage slows it down and can cause stomata to close, limiting CO₂ intake.
LINK BETWEEN RESPIRATION AND PHOTOSYNTHESIS
Cells need constant energy but store little ATP, so they regenerate it using energy from glucose.
Animals get glucose from food, while plants make it through photosynthesis.
The energy stored in glucose is released by cellular respiration and used to make ATP
