ch 7 Flashcards
define energy
the capacity to do work and transfer heat
2 major types of energy
potential: stored energy
kinetic: energy in motion
explain the 2 laws of thermodynamics
First law of thermodynamics:
law of energy
conservation
energy cannot be
created or destroyed,
but it can be changed
from one form to
another
Second Law of thermodynamics:
energy cannot be changed from one form to another without a loss of usable energy
exergonic reaction
ex
ones in which free energy value is negative
ex. complex carbs —> simple sugars
endergonic reaction
ex
ones in which free energy is positive
ex. simple sugars —> complex carbs
what is an enzyme’s function in a reaction
enzymes speed up reactions by lowering activation energy
what factors affect enzymatic activity?
how do they affect enzymes
- substrate
concentration
With increasing concentration of substrate molecules, the rate of reaction increases until the active sites on all the enzyme molecules are filled, at which point the max rate of reaction is reached
- enzyme concentration
cell regulates metabolism by regulating which enzymes are produced and active in the cell
- temperature
the enzymatic activity increases with increasing temp until the enzyme, a protein, is denatured by heat and inactivated. At this point the reaction rate falls steeply
- pH
strongly acidic or strongly basic pH can also cause denaturation of the tertiary structure
what are the 2 major types of enzymatic inhibition
competitive inhibitor: bind to the ACTIVE site of an enzyme
these compete with the substrate to bind to the enzyme first
noncompetitive inhibitor:
bind to another part of an enzyme causing the enzyme and its active site to change shape
its more difficult for substrate to bind to the altered active site and initiate the reaction
define oxidation and reduction in terms of electron transfer
oxidation is the loss of electrons
reduction is the gain of electrons
phases of cellular respiration?
What products are produced at each phase? What
is the total calculated ATP made from each phase. Where does each phase occur in bacteria?
Glycolysis: occurs in cytoplasm
2 pyruvates
2 NADH
2 H2O
2 net ATP
Transition Step: cytoplasm
2 CO2
2 NADH
2 Acety CoA
0 net ATP
Krebs Cycle: occurs in cytoplasm
4 CO2
2 net ATP
6 NADH
2 FADH2
ONLY MADE 4 ATP NEED 38 ATP IN TOTAL
made a lot of electron carriers has to go to ETC
Electron Transport Chain:
Electron carriers NADH and FADH electrons transport through the cytochromes in the ETC in the plasma membrane.
Protons from the electron carriers NADH and FADH get pumped out of the ETC into the periplasmic space. This leads to a buildup of a proton gradient which drives the enzyme ATP synthase. The energy of the pumping out the protons comes from the high energy electrons NADH and FADH. ATP synthase allows the protons to flow through and takes ADP and Pi to make ATP. The ADP and Pi are already in the cell but the protons help to bond the two together. This makes 34 ATP.
Resulting in the final 38 ATP needed.
What are the two types of fermentation? What happens to pyruvate in each case? What are the
end products of both pathways
Lactic Acid:
pyruvic acid gets transferred into lactic acid by pyruvic acid becoming reduced.
NADH becomes oxidized into NAD+
NAD+ is recycled back to glycolysis
Ethyl alcohol:
pyruvic acid loses a CO2 becoming
Acetaldehyde
Acetaldehyde is reduced to Ethyl Alcohol
NADH is oxidized to NAD+
NAD+ is recyled back to glycolysis
What drives ATP synthase to make ATP?
the high energy from the proton concentration gradient flows through ATP synthase binding ADP and Pi to make ATP.
What is anaerobic respiration, how is it different than aerobic? Do both produce large amounts
of ATP?
Anaerobic respiration does not use oxygen. This respiration produces a small amount of ATP (2 ATP). Anaerobic respiration has to go through this cycle again and again because it produces a small amount of ATP.
Aerobic respiration uses oxygen. This respiration produces a large amount of ATP (38 ATP).
active and passive transport in the ETC
active transport occurs in the ETC when the protons are getting pumped out of the ETC. Resulting in a buildup of high proton concentration gradient. It is going from an area of low concentration to an area of high concentration
passive transport occurs in the ETC when the protons flow through ATP synthase. It is going from an area of high concentration to an area of low concentration.
