Chapter 9: Cellular Respiration Questions from Notes Flashcards
Where do organisms get energy?
Organisms get the energy they need from food.
Food molecules contain ________ energy.
chemical
The chemical energy in food molecules is released when the bonds are ______.
broken
When are the bonds broken in food molecules?
The bonds are broken in food molecules during digestion.
A ______ is the amount of energy needed to raise the temperature of 1 gram of water by 1 degree C.
calorie
What are three types of molecules cells use for food?
fats, proteins, and carbohydrates
Cells break down food molecules _________.
Cells break down food molecules gradually.
The energy stored in food molecules ____, because their chemical structure bonds differ.
vary
Cells break down food molecules _________.
gradually
Cells use the energy stored in the chemical bonds to produce ___________ that power the activities of the cell.
compounds (such as ATP)
What is the squiggly thing in the mitochondria called?
Cristae
True or false: A human that doesn’t exercise will have cristae in cells that is “looser” than an active human.
True
What carries oxygen throughout the body?
Blood
Cellular respiration is the process that what?
Cellular respiration is the process that releases energy from food in the presence of oxygen.
Why can’t dead organisms digest food or go through cellular respiration?
Cellular respiration only occurs in the presence of oxygen.
What is the chemical reaction equation for cellular respiration?
6 O2 + C6 H12 O6 ______> 6 CO2 _ 6 H2O + energy
What is the chemical reaction equation in words for cellular respiration?
Oxygen + Glucose _______> Carbon dioxide (as a by-product, breathing) + water + energy
All fluids in the cell are _____-based.
water
What type of fluid is outside the cell?
extracellular
Why does the cell have to release chemical energy in food molecules gradually?
If the the cell released it at once, then most of the energy would be lost in the form of heat and light.
Photosynthesis and cellular respiration are _______ cycles.
opposite
What are the three main stages of cellular respiration?
Glycolysis, the Krebs cycle, and the electron transport chain
What is the translation of glycolysis?
“destroy the sweet”
Does glycolysis require oxygen?
No, glycolysis does not require oxygen.
Glycolysis produces a ____ amount of energy.
small
Most of glucose’s energy remains locked in the chemical bonds of _______ ___ at the end of glycolysis.
pyruvic acid
True or false: More energy is generated from pyruvic acid during the Krebs cycle.
True
What stage of cellular respiration produces the most energy?
the electron transport chain
What is the electron carrier in the electron transport chain?
Oxygen
Pathways of cellular respiration that require oxygen are ______.
aerobic
What two stages of cellular respiration require oxygen (aerobic)?
Krebs Cycle and electron transport chain
Where do the Krebs Cycle and the electron transport chain take place?
Inside the mitochondria
Pathways of cellular respiration that do not directly require oxygen are ________.
anaerobic
What stage of cellular respiration does not directly require oxygen (anaerobic)?
glycolysis
Where does glycolysis take place?
In the cytoplasm
What is the relationship between photosynthesis and cellular respiration?
Photosynthesis removes carbon dioxide from the atmosphere, and cellular respiration puts it back. Photosynthesis releases oxygen in the atmosphere, and cellular respiration uses that oxygen to release energy from food.
The ______ of cellular respiration are the ______ of photosynthesis, and vice versa.
The reactants of cellular respiration are the products of photosynthesis, and vice versa.
The release of energy by cellular respiration takes place in what?
Most organisms
The energy capture by photosynthesis occurs only in what?
plants, algae, and some bacteria
How efficient is glucose?
66%
What happens during glycolysis?
1 molecule of glucose (C 6) is transformed into 2 molecules of pyruvic acid (C 3)
What does glycolysis use?
1 molecule of glucose
2 ATP
2 NAD+
How many ATP molecules are produced during glycolysis?
4 ATP molecules
During glycolysis, what electron carrier accepts a pair of high-energy electrons?
NAD+
What does NAD+ become when it accepts the two high-energy electrons?
NADH
Where does NADH carry the high-energy electrons?
the electron transport chain
Why are the high-energy electrons taken to the electron transport chain?
The high-energy electrons will be used to produce more ATP.
How many NADH molecules are produced for every molecule of glucose that enters glycolysis?
2 NADH molecules
What is the purpose of cellular respiration?
The purpose of cellular respiration is to produce energy (ATP) for an organism.
What are two advantages of glycolysis?
- Produces ATP very quickly (supply energy demands)
2. Does not require oxygen
For every 1 molecule of pyruvic acid, there is _ Krebs Cycle.
1
During the Krebs Cycle, pyruvic acid is _____ ___ ___ _______ _______ in a series of energy-extracting reactions.
During the Krebs Cycle, pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions.
Where is the pyruvic acid broken down during the Krebs Cycle?
In the matrix of the mitochondria
When a carbon bond is broken, electrons break, what gathers the electrons?
NAD+
Why is the Krebs Cycle also known as the citric acid cycle?
The Krebs Cycle is also known as the citric acid cycle because citric acid is the first compound formed in the series of reactions.
The matrix is the __________ compartment of the mitochondrion.
innermost
When pyruvic acid enters the mitochondrial matrix, NAD+ accepts _ ____-______ _______ to form NADH.
2 high-energy electrons
One molecule of ___ is immediately produced when NAD+ becomes NADH.
CO2
What reacts to form acetyl-CoA?
the remaining 2 carbon atoms
What combines together to produce citric acid?
Acetyl-CoA and a C4 molecule
For every 1 molecule of glucose _ molecule of ATP is made during cellular respiration.
For every 1 molecule of glucose 1 molecule of ATP is made during cellular respiration.
During the energy extraction of the Krebs Cycle, when one molecule of CO2 is released from the _ carbon citric acid, the acid is broken down into a 5 carbon compound.
During the energy extraction of the Krebs Cycle, when one molecule of CO2 is released from the 6 carbon citric acid, the acid is broken down into a 5 carbon compound.
Every time a carbon bond is broken, energy is released, and so are ___ ________.
Every time a carbon bond is broken, energy is released, and so are two electrons.
What carries the electrons from the breaking of carbon bonds for CO2?
NAD+
What does NAD+ become when it picks up two electrons?
NADH
There are 2 pyruvates that enter the Krebs Cycle; therefore, the Krebs Cycle must “turn” ______.
twice
After the citric acid is broken down into a C5 compound, and electrons are given to NAD+, the compound then becomes a __ compound.
C4
When the C4 compound’s structure changes the first time, an ___ molecule becomes an ___ molecule.
ADP, ATP
When the C4 compound’s structure changes a second time, “crumbs” are dropped and ___ picks up the electrons and becomes _____.
When the C4 compound’s structure changes a second time, “crumbs” are dropped and FAD picks up the electrons and becomes FADH2.
During one Krebs Cycle, _ NADPH are produced.
4 NADH
During one Krebs Cycle, _ FADH2 is produced.
1 FADH2
During one Krebs Cycle, _ ATP is produced.
1 ATP
During one Krebs Cycle, _ molecules of CO2 are produced as by-products.
3 CO2
Where do the NADH and FADH2 go after being filled?
to the electron transport chain
NADH and FADH2 pass their high-energy electrons to _______ _______ ______ in the electron transport chain.
NADH and FADH2 pass their high-energy electrons to electron carrier proteins in the electron transport chain.
Energy generated by the electron transport chain is used to move __ ____ against a _______ _______ across the inner mitochondrial membrane and into the inter membrane space.
Energy generated by the electron transport chain is used to move H+ ions against a concentration gradient across the inner mitochondrial membrane and into the inter membrane space.
The inter membrane space of the mitochondria has a _______ concentration than the inner mitochondrial membrane (matrix).
higher
How do H+ ions pass back across the mitochondrial membrane?
Through the ATP synthase (it spins)
What is the net total of ATP molecules produced from cellular respiration?
36 molecules
What is the actual total (including the replacement ATP) of molecules?
38 molecules
How much energy is released as heat from cellular respiration?
64%
What is cellular respiration’s efficiency?
66%
Other than glucose, what are other sources that the cells can use to break down for energy?
Complex carbohydrates, lipids (fats), and proteins
What does chemiosmosis mean?
ion movement
Passive movement–requires no energy
chemiosmosis
An example of chemiosmosis in the electron transport chain is what?
the H+ ions moving from a high to low concentration
True or False: Chemiosmosis of protons is responsible for ATP
True
Lipids and proteins have a ____ energy release compared to carbohydrates.
slow
How many ATP molecules are necessary to break a C6 glucose in 2 C3 pyruvates?
2 ATP molecules
During the Krebs Cycle, what 2 carbon compound reacts to form acetyl-CoA?
acetic acid
The only purpose for the Coenzyme A is to move the C2 acetic acid to the __ compound.
The only purpose for the Coenzyme A is to move the C2 acetic acid to the C4 compound.
What is the net amount of ATP molecules produced during glycolysis?
2 ATP
How many NADH carriers are produced during glycolysis?
2 NADH
How many ATP are produced from the Krebs Cycle?
2 ATP
How many ATP are produced from the electron transport chain?
32 ATP
1000 calories = 1 ______ or ______
kilocalorie or Calorie
___% of energy is lost when glucose is broken down in glycolysis.
10%
