Cellular Respiration and Photosynthesis ER Flashcards
What is cellular respiration?
Cellular respiration is the process by which the energy contained in glucose molecules is made available for all the active processes within the cell
In what molecule is the energy from the cellular respiration of glucose stored?
Adenosine Triphosphate (ATP)
List the two ways in which cellular respiration can occur
Anaerobic and Aerobic Cellular Respiration
List the three steps of Aerobic Respiration?
- Glycolysis
- Kreb’s Cycle
- Oxidative phosphorylation (Adding phosphate group to ADP) or Electron Transport Chain (ETP)
Where does glycolysis occur in?
In the cytoplasm
Where does the Kreb’s cycle occur in?
In the mitochondrial matrix
Where does the Electron Transport Chain occur in?
In the mitochondrial cristae (folds of inner membrane)
Is Glycolysis Aerobic or Anaerobic?
Glycolysis is an anaerobic process (does not require oxygen)
What are the net products of glycolysis?
- 2 pyruvate molecules
- 2 ATP
- 2 NADH
What is required to synthesize NADH in glycolysis?
Hydrogen and electrons
Is Kreb’s cycle aerobic or anaerobic?
Aerobic
What are the other names for Kreb’s cycle
Tricarboxylic/citric acid cycle
For each pyruvate molecule in one Kreb’s cycle how many of each coenzyme is produced?
3 NADH and 1 FADH2
How many times does the Kreb’s cycle occur? Why? What are the changes in product quantities
It occurs twice because one pyruvate molecule of glycolysis is C3H6O6.
So, to catabolize 2 molecules of pyruvate with double molecules in one glucose, the cycle must repeat twice.
Which form of glycolysized product enters Kreb’s cycle
1 Acetyl CoA for 1 pyruvate molecule
What products continue onto the Electron Transport Chain
NADH and FADH2
What are NADH and FADH2
Coenzymes and electron carrier molecules
Is the ETC aerobic or anaerobic? What is the reactant
Aerobic; Oxygen is reactant
What is the other name for ETC?
Oxidative Phosphorylation
What is the main role of NADH and FADH2 in ETC?
To carry electrons to the inner mitochondrial membrane (cristae) and release them
Outline the process which electrons undergo after release in the Cristae in ETC?
They pass through a series of proteins in the inner mitochondrial membrane called electron carriers. As the electrons pass from one to the next, energy is released, which is used to convert ADP into ATP with the help of ATP synthase
Identify what finally occurs with the electrons in ETC?
The electrons reunite with protons (H+) and molecular oxygen (02) to form Water (H20)
List are the two types of anaerobic respiration?
Lactic acid fermentation and Alcohol fermentation
Do plants carry out alcohol or lactic acid fermentation?
alcohol
Do animals and bacteria carry out alcohol or lactic acid fermentation?
lactic acid
What is the equation for lactate fermentation
Glucose -> 2 Lactate group + 2ATP
State when lactic acid ferments?
In humans, when oxygen supply is low and slow. lactic acid can then be converted back into pyruvate when oxygen supply goes back up. This becomes part of the Kreb’s cycle.
Alcohol fermentation plant example
Sugarcane
What is the equation for alcohol fermentation?
Glucose -> 2 Ethanol + 2CO2 + 2ATP
Ethanol for plants; Effect on anaerobic respiration
Ethanol is toxic to plants therefore anaerobic respiration is short lived; e.g. in water-logged plants
Explain why photosynthesis and cellular respiration are interdependent
Photosynthesis input is carbon dioxide and water
which is Cellular respiration’s output
The output of photosynthesis which is glucose and oxygen is input for cellular respiration.
Photosynthesis
Photosynthesis is a biochemical process, in producers, that uses light energy and raw materials like carbon dioxide and water, to make organic compounds.
Adenosine Triphosphate (ATP)
ATP is a complex organic nucleotide chemical that provides energy to drive many biological processes such as muscle contraction.
What is NADP+ known as
Universal electron carrier
NADP+ to NADPH equation
NADP + electrons + hydrogen –> NADPH
NADH and FADH2 functions
NADH and FADH2 transport electrons (energy) from one section of mitochondria to another during cellular respiration.
Simplified photosynthesis equation
sunlight
6CO2 + 6H20 –> C6H12O6 + 6O2 chlorophyll
Where does the light dependent reactions take place?
Grana
What is photolysis?
Light energy from the Sun (photons) is absorbed by the chlorophyll to produce ATP (chemical energy)
This causes the photolysis of one water molecule to produce 1/2 O2, 2H+ and 2e-. This provides hydrogen ions for ATP from ADP production.
Where do light independent reactions occur?
Stroma
What are light independent reactions
H+ ions are used to reduce carbon dioxide dissolved in stroma (through Calvin cycle carbon fixation) into sugars
Limiting factor
Used to describe a factor that restricts the rate of a reaction, when limited, regardless of the level of other factors
Factors that affect the rate of respiration
As temperature increases, respiration rate increases, until as temperature gets too high it begins to drop again.
Above a certain temperature the enzymes involved denature.
As glucose available to the cell increases, respiration rate increases, until a maximum level is reached, plateauing.
Similarly, as oxygen levels increase, respiration rate increases, until a maximum level is reached, plateauing
Which energy products from the light dependent reactions are used in the light independent
ATP and NADPH
What is carbon fixation
When in the light-independent stage, carbon is synthesized into glucose. It is an anabolic reaction.
Aerobic respiration equation
Glucose + 6O2 -> 6CO2 + 6H20 + about 30-38ATP
Factors that affect the rate of photosynthesis?
Light intensity - is limiting but when saturation is reached, rate of photosynthesis plateaus
Carbon dioxide conc. - Carbon dioxide is limiting, but after a while saturation is reaches, resulting in plateauing
Temperature - Is optimally limiting. At this temperature, the maximum enzyme activity and collision rate of substate and enzymes, results in maximum photosynthetic efficiency, while at very low temperatures the collision rate is lowered. At very high temperatures however, enzymes denature, decreasing efficiency of photosynthetic reactions. Stomatic activity is also lowered in such conditions.
How many biochemical processes make up the glycolysis.
10
What is the chemical equation of pyruvate
C3H6O3
Why are cristae of the inner membrane folded?
To increase surface area; to maximize energy production via the electron transport chain (oxidative phosphorylation).
What is oxygen called in aerobic respiration?
Final electron acceptor: a steady supply is required.
What is the role of NADH
in cellular respiration, it carries one proton (H+) and 2 e-, at which point it has been reduced from NAD+ to NADH.
After delivery to the ETC, it is said to have been oxidized, back to NAD+
Why can’t lactic acid fermentation continue indefinitely?
Costs 6ATP each time for glucose regeneration in the liver
What is the “compensation point”.
When the uptake of carbon dioxide in cellular respiration, is equal to the production
What is yeast?
Eukaryotic fungus enzyme
Proportions of reduction and oxidization in fermentation of sugars.
2/3 of sugars were reduced to form alcohol
And a 1/3 was oxidized to form carbon dioxide
What is fermentation a consequence of
The multiplication of yeast
Why do mammals not produce ethanol?
Because they lack the enzymes needed for alcohol production
Lactate in mammals
pyruvic acid is metabolised into lactate and recycled back into glucose by the liver.
What are the two ways biofuels are collected?
From energy-enriched chemicals generated directly through the processes.
or derived from chemical conversion from biomass of living organisms, such as microalgae, plants and bacteria.
What is the main distinction between plants and algae?
Plants can photosynthesize
Photosynthetic pigment in bacteria?
Bacteriochlorophyll
