Metabolism (Exam2)
How many ATP molecules are formed from 1 NADH? And from 1 FADH2?
1 NADH = 3 ATP 1 FADH2 = 2 ATP
How are proteins used in metabolism?
1. structural components and form amino acids - Proteins can't be stored for later, so excess proteins are converted into glucose or triglycerides to be used in metabolism and supply energy. 2. Amino group is removed and converted into ammonium to enter krebs cycle in Deamination 3. Amino acids go through Decarboxylation when CO2 is removed 4. Amino acids are turned into pyruvic acid → Acetyl CoA which is used in Krebs Cycle
What products are formed for 1 acetyl-CoA that enters the Krebs cycle?
2 Co2, 1 GTP, 1 ATP (total ATP: 2), NADH, FADH2
How many ATP molecules are formed from the complete oxidation of glucose in bacteria?
38 (Glycolysis: 2 ATP, Krebs: 2 ATP, ETC: 34 ATP)
What is the Electron transport chain?
A sequence of electron carrier molecules that moves hydrogen ions across a membrane to produce the most amount of the ATP a cell needs to drive its processes. Products of ETC: 10 NADH (1 NADH = 3 ATP), 2 FADH2 (1 FADH2 = 2 ATP), Total ATP: 34
List 4 fermentation products and the organisms that produce these products
Alcohol (ethanol) → Yeasts, fungi, and bacteria Lactic Acid - Streptococcus and Lactobacillus (Homolactic bacteria) Hydrogen gas (H2) → photosynthetic bacteria, photoheterotroph bacteria, chemoheterotrophic bacteria Carbon Dioxide → Yeasts
How is lactic acid fermentation different from Alcohol fermentation?
Alcohol fermentation converts pyruvate into CO2 and Ethanol. Lactic acid fermentation converts pyruvate to lactic acid. Alcohol fermentation usually occurs in bread and beverages while Lactic acid occurs in the muscles.
What are cytochromes?
An enzyme that catalyzes redox reactions (part of oxidoreductase enzyme class). It is used in the ETC as Cytochrome C in the intermembrane space - carries one electron from Complex III to Complex IV.
What is the difference between chemoheterotroph and chemoautotroph?
Chemoautotrophs - Able to make their own food through chemosynthesis. They use CO2 as a carbon source and oxidize inorganic compounds like hydrogen sulfide, sulfur, and ammonia for energy. Found in hostile habitats.' Chemoheterotrophs - Not able to fix carbon to form their own organic compounds. They depend on organic compounds for energy and carbon source (lipids, proteins, and carbohydrates). Includes fungi and bacteria
What is fermentation?
Defined as a process that: 1. Releases energy from sugars or other organic molecules 2. O2 is not required but can occur 3. Krebs or ETC is not required 4. Uses organic molecules synthesized in a cell as final electron acceptor
beta oxidation
Fatty acid (long carbon chain) - in beta oxidation, removes 2 carbon at a time. The digestion of fatty acids (using Coenzyme A - CoA) to create Acetyl CoA used in Krebs Cycle.
How is fermentation different from cellular respiration?
Fermentation does not require Krebs, ETC, or O2. Fermentation is the partial degradation of sugars or other organic fuel without O2 while cellular respiration requires O2. Fermentation creates a steady supply of NAD and NADP needed for glycolysis (cellular respiration) to continue . Cellular respiration results in the complete oxidation of glucose into CO2 and H2O
For anaerobic respiration, what are the final electron acceptors?
O2
What is the difference between photoheterotroph and photoautotroph?
Photoheterotrophs - Use sunlight as source of energy but cant use carbon dioxide as their only carbon source. They use organic compounds from environment as their source of carbon. Photoautotrophs - Use photosynthesis to produce food using light, water, and carbon dioxide by converting H2O and CO2 into organic compounds (carbs, fats, and proteins) which are used in cellular functions.
What is the difference chemotrophs and phototrophs?
Phototrophs capture light energy and convert it to chemical energy and carbon for inorganic compounds. 1. Photoautotrophs 2. Photoheterotrophs Chemotrophs get their energy from oxidation of carbon dioxide or inorganic chemical compounds. 1. Chemoautotrophs 2. Chemoheterotrophs
Decarboxylation
Reaction that removes a carboxyl group and releases CO2. Occurs AFTER glycolysis and BEFORE the Krebs cycle as pyruvate is turned into Acetyl CoA. Inside the Krebs cycle, Isocitric acid is also decarboxylated to form Alpha Ketoglutaric acid and releases Co2 & NADH.
What are the starting materials for the Krebs cycle? And what is the first intermediate product?
Starting material: Pyruvic Acid that goes through oxidative decarboxylation to form Acetyl CoA. First intermediate product: citric acid.
Describe chemiosmosis
The movement of ions across a selectively permeable membrane to create a proton gradient. Hydrogen ions move from the lower concentration (matrix) of ions to a higher concentration (intermembrane space) of ions in ETC.
What is the purpose of the Krebs cycle?
To consume the pyruvate produced in glycolysis and make NADH and FADH to be used in the ETC and oxidative phosphorylation to make ATP.
