week 6 Flashcards
What are the two main sources of energy for bacterial metabolism?
Light (Phototrophs) and Chemicals (Chemotrophs)
What is the carbon source for heterotrophic bacteria?
Organic compounds
Do aerobic bacteria use oxygen as the final electron acceptor?
Yes, they use oxygen in cellular respiration and the electron transport chain (ETC)
How is ATP used in bacterial cells?
ATP stores energy in phosphodiester bonds, which release energy when broken
Name three reduced electron carriers used in bacterial metabolism.
NADH, NADPH, and FADH₂
What role does the electron transport chain play in energy production?
It creates a charge gradient across the membrane, allowing ions to flow and generate ATP
How do bacteria metabolize proteins?
Proteins are cleaved into amino acids by proteases, which enter the TCA cycle
Define catabolism and anabolism.
Catabolism breaks down molecules, while anabolism builds larger molecules from smaller ones
What is the significance of the gut microbiome in human digestion?
It helps digest indigestible materials, affecting nutrient absorption and health
What are the three main pathways of glucose catabolism?
Glycolysis (EMP), Entner-Doudoroff (ED), and Pentose Phosphate Pathway (PPP)
What does glycolysis (EMP pathway) generate from one glucose molecule?
4 ATP (net gain of 2), 2 NADH, and 2 pyruvates
How does the Entner-Doudoroff pathway differ from glycolysis?
It uses 1 ATP and produces 2 ATP, 1 NADH, 1 NADPH, and 2 pyruvates
What is the primary purpose of the Pentose Phosphate Pathway?
Biosynthesis of carbon-based molecules (e.g., nucleic acids, amino acids), generating 2 NADPH and 1 ATP
What happens to pyruvate after glycolysis if oxygen is not available?
It undergoes fermentation, producing various end products depending on the bacteria and intermediates
What is the result of pyruvate respiration in aerobic bacteria?
Complete breakdown to CO₂, generating ATP, NADH, FADH₂, and CO₂ through the TCA/Krebs cycle
