Chapter 10 Flashcards
What is metabolism?
the total of all chemical reactions in the cell and is divided into catabolism and anabolism
What is catabolism?
fuels reactions
energy conserving reaction
provide source of energy
generate precursors for biosynthesis
What is anabolism?
the synthesis of complex organic molecules from simpler ones; requires energy
Where are microbes represented in metabolism?
all five stages
What type of work is the synthesis of complex molecules?
chemical work
What type of work is the take up of nutrients, eliminates wast, and maintains ion balances?
transport work
What type of work moves the cell and the structures within?
mechanical work
What is a science that analyzes energy change in a system?
thermodynamics
First law of thermodynamics?
energy cannot be created nor destroyed
What is the second law of thermodynamics?
chemical and physical processes proceed in a way of disorder?
What is entropy?
amount of disorder in a system
What is a calorie?
amount of heat energy needed to raise 1 gram of water a degree
What is a Joule?
unit of work; 1 cal equals 4.1840 J
What is free energy?
the change in energy that can occur in chemical reactions
What is positive delta G
non spontaneous reaction
What is negative delta G
spontaneous reaction
What is delta G?
free energy change
What is delta H?
change in enthalpy (HEAT)
What is delta S?
change in entropy
What is the equation for equilibrium?
A + B ⇌ C + D
When is equilibrium reached?
when forward rate is equal to reverse rate
What influences free energy change?
concentration, pressure, temp, and pH
What are exergonic reactions?
negative delta G
What are endergonic reactions?
positive delta G
What is the energy currency of the cell?
ATP
How is the breakdown of ATP favored?
exergonic breakdown of ATP to endergonic reactions
What are some other energy sources?
GTP, CTP, and UTP
What does ATP have a high transfer rate of?
Phosphate
Oxidation Reduction Reactions do what with electrons?
are donated to an acceptor
What does donating an electron do?
release of energy which can be stored as ATP
What does it mean if a molecule has a lot of electrons?
it is more energy rich
What is a Redox: two half reaction?
One electron is donating (oxidizing reaction) and one electron is accepting (reducing reaction)
How are the acceptor and donor paired in a redox two half reaction?
Conjugate redox pair
What is the equilibrium constant for an oxidation reduction reaction?
standard redox potential
What is a better electron donor?
more negative
What is a better electron acceptor?
more positive
What does it mean if the difference between the charge of the donor and the charge of the acceptor is greater?
the more negative the delta G is
What is the organization of electron carriers?
Electron Transport Chain
In the ETC, the first electron carrie is the most what?
negative
The potential energy in the first redox couple is released and used to form what?
ATP
The first carrier is reduced and what happens next?
the carrier moves up and so on
Where are electron carriers located in bacteria and archaea?
in the plasma membrane
Where are the electrons located in eukaryotic cells?
in the internal mitochondrial membrane
What are examples of electron carriers?
NAD, NADP, FAD, FMN, CoQ, Cytochromes, Nonheme iron sulfer proteins
What do cytochromes use to transfer electrons?
iron, and iron is apart of the heme group
What do nonheme iron-sulfur proteins use to transfer electrons?
iron, and iron is NOT apart of the heme group
What from biochemical pathways?
enzymes
How are pathways connected?
through networks
What do enzymes do?
carry out reactions at physiological conditions
How do enzymes help reactions?
that speed up the rate at which they reach equilibrium
What are substrates?
reacting molecules
What are products?
substances formed by reactions
How are some enzymes composed?
one or more polypeptides or the same but no nonprotein components
What is the protein component of the enzyme?
apoenzyme
What is the nonprotein component of the enzyme?
cofactor
How are coenzymes attached?
loosely
What is a holoenzyme?
apoenzyme and a cofactor
What do enzymes do to the activation rate?
lower it
How do enzymes lower activation rate?
increase concentration of substrate, the transition state complex, and the fit model for the interaction
What environmental factors impact enzyme activity?
substrate concentration
pH
temperature
As rate of reaction increases what also increases?
substrate concentration
Where are enzymes most optimal?
at specific pH and temp
What is denaturation?
loss of enzyme structure and activity
What inhibitor directly competes with the binding of substrate?
competitive inhibitor
What inhibitor binds changes the enzyme’s shape so it becomes less active?
noncompetitive inhibitor
What three mechanisms regulate metabolism?
Metabolic channeling
Enzyme synthesis
Direct stimulation or inhibition
What is the differential localization of enzymes and metabolites?
Metabolic Channeling
What is compartmentation?
distribution of enzymes among separate cell structures or organelles
What is an allosteric regulation?
changes shape of enzyme and alters activity of catalytic site.
What type of effector increases enzyme activity?
postive effector
What type of effector inhibits enzyme?
negative effector
How do covalent modifications effect enzymes?
add or remove chemical group?
What is the advantage to adding or removing the chemical group?
responds to more stimuli
adds second level of control
What enzyme is involved with feedback inhibition?
pacemaker enzyme
What does the pacemaker enzyme do?
catalyzes the slowest reaction in the pathway
What are isoenzymes?
enzymes that catalyze the same reaction
