Cellular Respiration Flashcards
What does cellular respiration accomplish?
It causes ATP to release energy for cellular metabolic processes
What is the energy from cellular respiration used to do?
Active transport of molecules across the cell membrane, protein synthesis, and muscle contractions
What’s the chemical equation for cellular respiration?
C6H1206+6O2»_space; 6CO2+6H2O+energy (ATP)
What type of process is cellular respiration overall? (Aerobic or anaerobic)
It’s aerobic
Define aerobic
It means it requires the presence of oxygen
Define anaerobic
Something that doesn’t require the presence of oxygen
What types of “trophs” undergo Cellular respiration?
Both heterotrophs and autotroph’s undergo cellular respiration
What are the three major steps of cellular respiration?
Glycolysis, the Krebs cycle, and the electron transport chain
Is glycolysis anaerobic or aerobic?
Anaerobic
Is the Krebs cycle anaerobic or aerobic?
Aerobic
Is the electron transport chain anaerobic or aerobic?
Aerobic
What are three energy carriers in cellular respiration?
ATP, NADH, and FADH2
What part of the cell does glycolysis take place in?
In the cytoplasm of the cell
What is the net production of ATP during glycolysis?
2 ATP
How many ATP does it take to start glycolysis?
2 ATP
How many ATP molecules does glycolysis make?
4 molecules but it takes 2 of those molecules of ATP for the cycle of glycolysis to start over again
Where does the resulting NADH from glycolysis go?
To the electron transport chain
What does one reaction of glycolysis do involving the production of NADH?
One reaction of glycolysis removes four high energy electrons, passing them to an electron carrier called
NAD+
How does NAD+ turn into NADH during glycolysis?
Each NAD+ accepts a pair of high-energy electrons and becomes an NADH molecule
What is the main goal of glycolysis?
To create pyruvic acid
Where do the Pyruvic acid molecules go to after glycolysis?
The Krebs cycle
What’s another name for the Krebs cycle?
The citric acid cycle
Where do the two net ATP molecules go to after glycolysis?
They’re just usable energy for the cell
If oxygen is present, then what happens after glycolysis?
The Krebs cycle
If oxygen is not present, then what happens after glycolysis?
Fermentation
What is one advantage of glycolysis?
The process of glycolysis is so fast that cells can produce thousands of ATP molecules in a few milliseconds
What are 2 names for what happens before the Krebs cycle and after glycolysis?
Pre-Krebs cycle or Acetyl-CoA
Before pyruvic acid enters the Krebs cycle, what happens?
It combines with an enzyme called Coenzyme A (CoA) to produce a molecule of Acetyl CoA
What is Acetyl CoA?
It’s a molecule produced by almost all nutrients (carbs, proteins, lipids, etc) before entering the Krebs cycle
What is the pathway to the Krebs cycle?
It goes from:
Glycolysis > Pyruvic acid > Acetyl CoA > Krebs cycle
What is the Krebs cycle?
It’s a cyclical series of oxidation reactions that give off CO2 and produce 1ATP per cycle
How many times is the Krebs cycle have to turn per glucose molecule?
It has to turn twice for every one glucose molecule
How many ATP does the Krebs cycle produce?
2
Where does the Krebs cycle take place?
In the inner membrane of the mitochondria
What does Acetyl CoA combine with and what does it form? (during the Krebs cycle)
Acetyl CoA combines with a four carbon molecule to make a molecule citric acid
What is citric acid used for in the Krebs cycle?
It is broken down in several steps which provides energy to make NADH, FADH2, and ATP
What 2 things are removed during the Krebs cycle? What do they do?
One carbon molecule is removed which forms CO2
Electrons are removed, which changes NAD+ to NADH
What does coenzyme A join during the Krebs cycle and what does it form?
Coenzyme A joins the two carbon molecule which forms Acetyl CoA
What happens to the Acetyl CoA that is formed when Coenzyme A joins the two carbon molecule? (In the Krebs cycle)
Acetyl CoA then add the 2-carbon Acetyl group to a 4-carbon compound, which forms citric acid
What is a byproduct of the Krebs cycle?
Carbon dioxide
What is the ETC? (Electron transport chain)
It’s a series of proteins located in the mitochondrial membrane
What does the ETC use high-energy electrons for?
It uses high-energy electrons from the NADH and FADH2 provided by the Krebs cycle to move H+ protons across the concentration gradient
Why are the H+ protons moved down the concentration gradient? How? (ETC)
These hydrogen protons pass back down the concentration gradient through the ATP synthase to form ATP
What is the ETC in cellular respiration similar to?
It’s similar to the ETC in the light reactions of photosynthesis
What is used as the final electron acceptor at the end of the ETC?
Oxygen
Describe the role of oxygen as an electron acceptor in the ETC
Oxygen receives electrons and hydrogen ions and produces a molecule of water
Where do high-energy electrons in the ETC come from?
NADH and FADH2
High-energy electrons passed down from _____ to _____ during the ETC
High-energy electrons are passed along the electron transport chain from one carrier protein to the next during the ETC
When high energy electrons move down the electron transport chain, what is their energy used for?
To move hydrogen ions across the membrane
Is the inter-membrane space positively charged or negatively charged? (Hint: it’s filled with H+ ions)
It’s positively charged
What does the enzyme do as the ATP synthase rotates?
As the ATP synthase rotates, the enzyme grabs a low energy ADP, attaching a phosphate to it and forming a high energy ATP
What is a byproduct of the ETC?
Water (H2O)
How many ATP is produced from the ETC?
34 ATP
When does fermentation happen?
When oxygen is not present, the products of glycolysis (pyruvic acid and NADH) enter an alternative process called fermentation
Give an example when fermentation can happen in the human body
When someone is conducting a high-level of activity and breathing doesn’t supply enough air for the cells’ activities
Where does fermentation occur in a cell?
In the cytosol of a cell
What are the two main types of fermentation?
Lactic acid fermentation and alcoholic fermentation
When does lactic acid fermentation happen?
When Pyruvic acid that accumulates as a result of glycolysis is converted into lactic acid
What is the purpose of lactic acid fermentation?
To regenerate NAD+ so that glycolysis can continue
What is the equation for lactic acid fermentation after glycolysis?
Pyruvic acid + NADH»_space; Lactic acid + NAD+
Besides animals and humans, when can lactic acid fermentation happen?
It can happen in some bacteria and molds
What are two edible products of lactic acid fermentation?
Different flavored cheese and yogurt
What types of organisms use alcoholic fermentation? What are their waste products?
Many yeasts and plants, which forms ethyl alcohol and carbon dioxide as wastes
What is the purpose of alcoholic fermentation?
It uses the products of glycolysis (NADH and Pyruvic acid) to provide enough NAD+ and ATP for glycolysis to continue
What is the chemical equation for alcoholic fermentation after glycolysis?
Pyruvic acid + NADH»_space; Alcohol + CO2 + NAD+
