remedial Flashcards
How many different amino acids are found in proteins?
20
What cycles provide the precursors to all amino acids?
- EMP cycle
- PPP cycle
- TCA cycle
What is the role of glutamate in amino acid metabolism?
Amino donor for most amino acids
What is the role of glutamine in amino acid synthesis?
Amino donor for the synthesis of purines, pyrimidines, amino sugars, histidine, tryptophan, asparagine, NAD+, and ρ-aminobenzoate
What enzyme synthesizes glutamate when [NH3] is high?
Glutamate dehydrogenase
What enzymes are used for glutamate synthesis when [NH3] is low?
- Glutamine synthetase
- Glutamate synthase (GOGAT)
How many intermediates do 20 amino acids degrade into for entry into the TCA cycle?
7
List the 7 intermediates that amino acids can be degraded into.
- Pyruvate
- Acetyl-CoA
- Acetoacetyl-CoA
- α-ketoglutarate
- Succinyl-CoA
- Fumarate
- Oxaloacetate
What are nucleic acids made up of?
Nucleotides
What roles do nucleotides play in metabolism?
- Fuel metabolic reactions through nucleotide triphosphate hydrolysis
- Serve as regulatory molecules
- Substrates for RNA and DNA synthesis
- Components of many coenzymes
What is photosynthesis?
Conversion of light energy into chemical energy
What do photosynthetic organisms obtain energy from?
Light
What is photophosphorylation?
The phosphorylation of ADP to ATP driven by light energy
What is the process that transfers electrons from H2O to NADP+ in some photosynthetic systems?
Photoreduction of NADP+
What type of photosynthesis produces oxygen?
Oxygenic photosynthesis
What are the two types of photosynthetic bacteria?
- Oxygenic
- Anoxygenic
What is the role of the acyl carrier protein in fatty acid synthesis?
Helps synthesize fatty acids 2 carbons at a time
What is the reductant used in fatty acid synthesis?
NADPH
Where does fatty acid biosynthesis occur in prokaryotes?
Cytosol
Where does fatty acid degradation occur in eukaryotes?
Matrix of the mitochondria
What is the ATP yield per oxidation cycle of fatty acids?
17
How is ATP generated from fatty acid activation?
Fatty acid + CoA + ATP → Acyl-CoA + AMP + 2(P)
What is fermentation?
A microbially mediated degradative and energy-yielding process
What are the three unifying characteristics of fermentation?
- NADH is oxidized to NAD+
- Electron acceptor is often pyruvate or a pyruvate derivative
- Oxidative phosphorylation cannot operate
What are the types of fermentation characterized by?
Excretion of large quantities of reduced organic compounds
What is lipid catabolism?
Process by which fatty acids are broken down to generate acetyl-CoA
What initiates lipid catabolism?
Action of lipases on lipids to produce glycerol and fatty acids
What is the role of autotrophic CO2 fixation in prokaryotes?
Incorporation of inorganic N and S into organic material
What are the essential components of all photosynthetic apparatus?
- Antenna of light harvesting pigments
- Photosynthetic reaction center
- Electron transport chain
What are the two types of photosynthetic pigments?
- Reaction center pigments
- Light harvesting pigments
What is the primary role of lipids in prokaryotes?
Component of membranes
What are the major lipids in bacteria and eukaryotes?
Phosphoglycerides
List the roles of lipids.
- Component of membranes
- Carrier in LPS/peptidoglycan synthesis
- Cell surface components
- Alternative forms of energy
- Protective coat of many organisms
