Exam 2 (Ch. 5, 6, 13) Flashcards
What is metabolism?
The buildup and breakdown of nutrients within a cell.
Describe the two types of pathways of metabolism
catabolic - break down macromolecules into simple ones, releasing energy
anabolic - build up macromolecules by combining simple ones, using energy
catabolic reactions provide the energy needed for anabolic reactions
Tue or false: Many metabolic pathways can be beneficial rather than pathogenic
True
metabolic pathways are determined by
enzymes
what do catalysts do in chemical reactions?
speed up chemical reactions without being altered
what do enzymes do in chemical reactions?
- enzymes are biological catalysts; speed up the reaction
- act on a specific substrate
- lower the activation energy
substrate contacts the enzyme’s active site to form ____
an enzyme substrate complex
Substrate is transformed and rearranged into ___ which are released from the enzyme
products
competitive inhibitors fill the ___ of an enzyme and compete with the ___
active site, substrate
Noncompetitive inhibitors interact with the ___
allosteric site
what is feedback inhibition?
when an enzyme’s activity is inhibited by the enzyme’s end product
oxidation: ___ of electrons
removal
reduction: ___ of electrons
gain
what is a redox reaction?
an oxidation reaction paired with a reduction reaction
ATP is generated by the ___ of ADP with the input of energy
phosphorylation
what generates ATP?
The phosphorylation of ADP with the input of energy
describe oxidative phosphorylation
electrons are transferred from one electron carrier to another along the electron transport chain on a membrane that releases energy to generate ATP
what is photophosphorylation?
light energy is converted to ATP during oxidation from chlorophyll
most microorganisms oxidize ___ as primary energy source
carbohydrates
what are the three stages of the breakdown of carbohydrates?
- glycolysis
- citric acid cycle
- electron transport chain
Summarize glycolysis
first phase - glucose is broken down to glyceraldehyde and uses energy
second phase - glyceraldehyde is broken down to 2 pyruvate and releases energy in the form of ATP and NADH
summarize acetyl-coA synthesis
- pyruvic acid (from glycolysis) is oxidized and decarboxylation (loss of co2) occurs
- the resulting two-carbon compound attached to coenzyme A attaches to coenzyme A, forming acetyl coA and NADH
what is decarboxylatiob?
loss of co2
what is aerobic respiration?
- the production of energy from food in the presence of oxygen
- glucose + oxygen –> carbon dioxide + water + atp
in anaerobic respiration, the final electron acceptor in the electron transport chain is not __
O2
which yields more energy, aerobic or anaerobic respiration?
aerobic
what are three molecules that can be the final electron acceptors in anaerobic respiration?
-NO3-
-SO4 2-
CO3 2-
true or false: fermentation does not require oxygen
true
does fermentation release or use energy?
release
fermentation uses a ___ molecule as the final electron acceptor
organic
describe homolactic and heterolactic fermentation
homolactic - produces lactic acid
heterolactic -produces lactic acid and/or other compounds
summarize alcohol fermentation
- 2 pyruvate (from glycolysis) is used to produce co2 and ethanol
- acetaldehyde acts as an electron acceptor and the 2 NADH is oxidized to 2 NAD+
summarize lactic acid fermentation
- 2 pyruvate (from glycolysis) is used to produce 2 lactate
- pyruvate acts as an electron acceptor allowing NADH to be oxidized to NAD+
where does each glycolysis process occur in the cell?
citric acid - mitochondria
fermentation - cytoplasm
etc - mitochondria
what are physical requirements for growth?
- temperature
- ph
- osmotic pressure