CHAPTER 5 Flashcards
What is metabolism?
collection of controlled biochemical reactions that take place within a microbe; all chemical and physical workings of a cell
Anabolism vs catabolism
anabolic pathways build up macromolecules by combining simpler molecules, using energy in the process. Catabolic pathways break down macromolecules into simple component parts, releasing energy in the process. Catabolic reactions provide the energy needed for anabolic reactions
Oxidation and reduction reactions
many metabolic reactions involve the transfer of electrons from an electron donor to an electron acceptor
oxidation- giving electron
reduction- receiving electron
occur simultaneously
What are the types of phosphorylation?
substrate level, oxidative, photophosphorylation
What is phosphorylation?
inorganic phosphate is added to substrate
What is substrate level phosphorylation?
The transfer of phosphate to ADP from another phosphorylated organic compound
What is oxidative phosphorylation?
The use of energy from redox reactions to attach inorganic phosphate to ADP
What is photophosphorylation?
uses proton motive force to generate ATP
What are enzymes?
organic catalysts
What are the 6 categories of enzymes?
hydrolases isomerases ligases and polymerases lyases oxidoreductases transferases
What is the makeup of enzymes?
many protein enzymes are complete in themselves;
apoenzymes are inactive if not bound to nonprotein cofactors;
binding of apoenzyme and its cofactors yields holoenzyme;
some are RNA molecules called ribozymes
Factors effecting rate of enzymatic reactions
temperature, pH;
enzyme and substrate concentrations;
presence of inhibitors
What is the effect of an enzyme on chemical reactions?
the chemical reaction requires much less activation energy
What controls enzymatic activity?
activators- some enzymes activated when cofactor binds to allosteric site
What are enzyme inhibitors?
substances that block an enzyme’s activity, include competitive and noncompetitive
What happens during competitive inhibition of enzyme activity?
inhibitory molecules which are similar in shape to substrate molecule, compete for and block active sites on the enzyme;
reversible inhibition can be overcome by an increase in substrate concentration
location of glycolysis?
cytoplasm
input of glycolysis?
glucose, 2 NAD+, 2 ATP, 4 ADP + 4 P
output of glycolysis?
2 pyruvate, 2 NADH, 2 ADP, 4 ATP NET GAIN 2 ATP
location of krebs cycle?
.prokaryotes- cytosol
eukaryotes- matrix of mitochondria
input of krebs cycle?
2 acetyl-CoA; 6 NAD+, 2 FAD, 2 ADP + 2 P
location of ETC?
prokaryotes- cytoplasmic membrane
eukaryotes- inner mitochondrial membrane
input of ETC?
10 NADH, 2 FADH2
output of ETC?
10 NAD+, 2 FAD +, 6 H20, 34 ATP
Why is ATP described as the currency of the cell?
- It is the energy molecule that all cells need in order to do anything within the human body.
- How is the energy in ATP released?
- Hydrolysis, bonds break releasing energy. A phosphate is removed converting ATP to ADP plus energy.
How is the energy in ATP released?
- Hydrolysis, bonds break releasing energy. A phosphate is removed converting ATP to ADP plus energy.
What type of bonds have to be broken to release the energy in ATP?
one phosphate bond
Describe the relationship between energy stored in food and ATP.
it is labeled as potential energy, but has to broken down through cellular respiration to be used.
How does the energy content in carbohydrates, lipids, and proteins differ?
carbs are used the most, lipids make the most but cant be easily broken down, and proteins are rarely used