Unit 7
What happens to the products of glycolysis in the absence of oxygen?
Undergo anaerobic fermentation processes (such as lactic acid fermentation or alcoholic fermentation) instead of entering the aerobic pathways
What process oxidizes acetyl CoA and where does it occur?
The citric acid cycle, and it occurs in the mitochondrial matrix
What are the two stages of chemiosmotic coupling?
ETC & Oxidative phosphorylation (ATP synthase)
Where in the cell does photosynthesis occur?
Cholorplast
What is a structure specific to chloroplasts that mitochondrions do not possess?
Stroma or Thylakoid Membrane are acceptable
Define the function of two of these terms; kinase, isomerase, dehydrogenase and mutase.
What molecule does acetyl CoA bind to when it enters the citric acid cycle? What molecule is formed?
It bonds to oxaloacetate, and they form citrate.
What is the final electron acceptor in the electron transport chain (ETC)?
Molecular Oxygen (O2)
What is the purpose of chlorophyll?
To capture light energy, and facilitate the conversion of carbon dioxide and water into glucose and oxygen using sunlight
What enzyme is responsible for the carbon fixation reaction?
Rubisco
What products are made by the citric
acid cycle, and how many of each?
NADH: 3 molecules of NADH
FADH2: 1 molecule of FADH2
ATP (or GTP): 1 molecule of ATP (or GTP, depending on the cell type)
Carbon Dioxide (CO2): 2 molecules
What is the function of cytochromes?
Facilitating the transfer of electrons in biochemical reactions, essentially the "taxis" of the ETC.
What are the two stages of photosynthesis and where do they occur?
Step 2: Dark reactions (give example)
What are the 3 phases or stages of glycolysis?
1.) Energy investment stage
2.) Cleavage Stage
3.) Energy generation phase
What is the role of glycolysis in catabolism, and where does it occur in the cell?
Breaks down glucose, a six-carbon sugar, into two molecules of pyruvate (three-carbons each). This process is crucial for:
What enzyme complex is used to convert pyruvate?
Pyruvate dehydrogenase complex
Describe the proton motive force. What are the two components?
It drives ATP synthesis in cells. It refers to the electrochemical gradient of protons (H+) across a membrane, generated by the electron transport chain (ETC). This gradient represents stored energy that can be utilized for various cellular processes.
Chemical Gradient (Concentration Gradient)
Electrical Gradient (Membrane Potential)
Where do the electrons from photosystem I end up? Where do the electrons from
photosystem II end up?
Electrons from photosystem II ultimately end up being transferred to photosystem I, and from there, they finally reach NADP+ (forming NADPH)
What is the start point of the Citric Acid Cycle?
Acetyl CoA binding to oxaloacetate
Define 2 of the following: cellular respiration, metabolism, catabolism, and anabolism?
Cellular Respiration: A metabolic pathway where cells convert biochemical energy from nutrients like glucose into usable energy in the form of ATP
Metabolism: Sum of all chemical reactions occurring in an organism; includes catabolism and anabolism
Catabolism: Breaking down large, complex molecules into smaller, simpler ones, releasing energy in the process, often used to generate ATP
Anabolism: Uses energy (like ATP) to synthesize complex molecules from smaller building blocks, essentially building up cellular components
What molecule must be re-generated for the citric acid cycle to continue, and why?
Oxaloacetate, because it binds to the Acetyl CoA which is the start point of the cycle.
Name in order the 3 respiratory enzyme complexes in the electron transport chain.
Complex I: NADH dehydrogenase
Complex II: Succinate dehydrogenase
Complex III: Cytochrome bc1 complex
Where does the Calvin Cycle occur?
In the stroma of the chloroplast?
Do all molecules have the same
redox potential?
No, different molecules have different redox potentials; each molecule has its own unique tendency to gain or lose electrons.