Ch. 4 Cellular Metabolism Flashcards
(35 cards)
within a cell a many thousands of _____________ take place to keep the cell in homeostasis
chemical reactions
examples of chemical reactions:
cellular respiration, protein synthesis, cell cycle, mitosis, meiosis, DNA replication
a constant __________________ is needed for these reactions and _________ control the rate at which these reactions take place
supply of energy
enzymes
the set of chemical reactions that acquire, store, and release energy in cells
cellular metabolism
comes from the chemical bonds of nutrient molecules from the diet
energy
anabolic reaction-
builds large molecules from small ones
ex) dehydration synthesis
catabolic reaction-
breakdown of large molecules to small ones
ex) hydrolysis
without _______ reactions in cells would not happen fast enough to keep cell in homeostasis
enzymes
metabolic reactions need ____
ATP
enzymes-
catalyst proteins that work by lowering the activation energy and speed rates of chemical reactions
enzymes are not ____________ in their function
consumed
each enzyme acts only on one specific __________
substrate
every cell contains _________________ to help complete reactions
hundred of enzymes
many enzymatic reactions are ___________
reversible
rate/speed of enzyme-controlled reactions depend on:
- number of enzymes & substrate in cell
- how many substrate process per second
factors that alter enzymes:
radiation, electricity, fluids with extreme pH values, certain chemicals
sequence of enzyme-controlled reactions
metabolic pathway
controls the entire rate of the metabolic pathway
regulatory enzyme
most metabolic reactions use ________________
chemical energy
held in the bonds between atoms of molecules and released when the bonds break
chemical energy
cells burn glucose in process called ____________
oxidation
cells only capture ____________ of energy released from breaking chemical bonds in cellular respiration
40%
3 stages of cellular respiration
Glycolysis
Krebs cycle
Electron transport chain
what is produced in each stage
1) 2ATP, 2 Pyruvate, NADH, electrons
2) CO2, 2ATP, NADH, FADH2, citric acid, electrons
3) H2O, Heat, 26-34 ATP