Chp. 5 A Flashcards
STUDYYYYYYY
What is metabolism?
The breakdown and buildup of material within a cell
What are the two types of chemical reaction monomers? Explain them
- Catabolic monomers: break down macromolecules into simple parts, releasing energy in the process
- Anabolic monomers: build up macromolecules by combining simpler molecules, using energy in the process
Anything that ends in ase is a _______
Anything that ends in ose is a ________
- Enzyme
- Sugar
Is cellular respiration catabolic or anabolic?
Catabolic
What is the collision theory?
Chemical reactions happen when atoms, ions, and molecules collide
What is the starting material and end material known as?
Substrate of reactant
Product of a reactant
Define activation energy
The collision energy required for a chemical reaction to occur
Define reaction rate
How fast it would take for collisions to occur to bring about a reaction
Enzymes _____ the activation energy and ______ the rate of reaction. They are ________
- Lower
- Increase
- Catalysts
What are the two parts of an enzyme?
- Active site
- Allosteric site
What is the purpose of the allosteric site?
Change the shape of the active site
What is an induced fit?
When the substrate moves into an active site and the site tightens around the substrate to keep it inside
The protein portion of an enzyme is the ______
Apoenzyme
The nonprotein portion of an enzyme is the ______
Cofactor
What are some examples of cofactors?
- Vitamins
- Minerals
- Metals
What are coenzymes?
Organic cofactors
An apoenzyme PLUS a cofactor is a _______
Holoenzyme
What does the cofactor do?
Helps the substrate fit into the apoenzyme
What factors will denature enzymes?
- High temperature
- High salt concentration
- High OR low pH
What factors will slow down an enzyme but not denature it?
- Low temperature
- Very slight change in pH
What factors will affect the rate of reaction?
- Substrate concentration (the more substrate, the longer the reaction takes)
- More enzyme: less time reaction takes place
What is the difference between exoenzymes and endoenzymes?
Exoenzymes are released outside of the cell and are not active inside of the cell whereas endoenzymes function and are active inside of the cell
What is a Turnover number?
What is the turnover number of enzymes?
- The number of substrate molecules an enzyme converts to a product per second
- 1- 10,000
Anabolic reactions that form covalent bonds between smaller substrate molecules are known as __________
Synthesis or condensation reactions
Catabolic reactions that break down substrates into smaller molecules and require water input to break bonds is known as ________
Hydrolysis
What is a competitive inhibitor and noncompetitive inhibitor?
Competitive inhibitor: competes with a substrate for the active site
Noncompetitive inhibitor: enzymes are regulated by the binding of molecules other than the substrate away from the active site
Explain competitive inhibition
- Both molecules compete for the active site
- Reaction proceeds
- Reaction is blocked because competitive inhibitor is incapable of becoming a product
Explain noncompetitive (allosteric) inhibition
- Enzyme substrate reaction proceeds, products are released
- A product of the enzyme reaction binds to the regulatory site and causes a change in the shape of the active site
- Substrate cannot fit, enzyme action is blocked
Where does Glycolysis take place in prokaryotes and eukaryotes?
Both take place in the cytoplasm
Where does the Krebs cycle take place in prokaryotes and eukaryotes?
P: Cytoplasm
E: Matrix of mitochondria
Where does the electron transport chain take place in prokaryotes and eukaryotes?
P: Cell/ plasma membrane
E: Inner mitochondrial membrane
Do prokaryotes require oxygen for the following:
- Glycolysis
- Krebs cycle
- Electron transport chain
- NO
- YES
- YES
Do eukaryotes require oxygen for the following:
- Glycolysis
- Krebs cycle
- Electron transport chain
- NO
- YES
- YES
NAD+ and FADH carry what?
Electrons
What is the net output of Glycolysis?
2 ATP
2 NADH
2 Pyruvic acids
What is the net output of the Krebs cycle?
4 CO2
6 NADH
2 ATP
2 FADH2
What is the net output of Electron transport and Oxidative Phosphorylation?
34 ATP
6 H2O
TRUE OR FALSE: Enzymes are nonspecific to a substrate
FALSE: Enzymes are specific to one substrate
Explain Glycolysis
Glucose (6c) is oxidized and split into 2 molecules of pyruvic acid (3C). NADH is generated
Explain the Krebs cycle
- Each pyruvic acid from glycolysis is oxidized and decarboxylation (loss of CO2) occurs
- The two carbon compound attaches to coenzyme A, forming Acetyl CoA and NADH
- Oxidation of acetyl CoA produces NADH, FADH2, and ATP, and liberates CO2 as waste
Explain chemiosmosis
- Electrons from NADH pass down the ETC while protons are pumped across the membrane
- It establishes proton gradient
- Protons in higher concentration on one side of the membrane diffuse through ATP synthase
- Movement causes phosphorylation of ADP to form ATP
Explain the electron transport chain. What is the final electron acceptor?
ETC is 4 protein complexes embedded in inner mitochondrial membrane. It accepts electrons from NADH and FADH. Generates energy (ATP) through oxidative phosphorylation
Final electron acceptor: O2
Explain oxidative phosphorylation in ETC
The electron transport chain is composed of 4 protein complexes embedded in the inner mitochondrial membrane.
- High-energy electrons are donated by NADH and FADH₂, which are produced earlier in cellular respiration
- These electrons pass through the complexes, and as they move through the chain, their energy is used to pump protons (H⁺ ions) from the mitochondrial matrix into the intermembrane space, creating a proton gradient.
- Oxygen (O₂) is the final electron acceptor at the end of the chain. It combines with electrons and protons to form water (H₂O). This is why oxygen is essential for oxidative phosphorylation.
