What is metabolism?
The total of all chemical activities in the cell
What is anabolism?
- When smaller substances link to form a complex molecule
- ex: amino acids forming a protein chain
- This is endergonic
What is catabolism?
- When complex molecules are broken down into their smaller components
- Ex: Degradation of starch to form a monosacchride
What are the components of ATP molecules?
- Phosphate groups
How is energy stored in ATP?
Through the transfer of phosphate groups
How does a phosphate group transfer trigger a biochemical reaction in the cell?
- When ADP gains a phosphate group to become ATP, the reaction is exergonic
- ATP uses the energy gained from the exergonic reaction to lose a phosphate group and give energy to other reactions in the cell
What does OIL RIG mean?
- Oxidation is loss
- Reduction is gain
What is the significance of redox reactions in the cell?
They are a significant part of cell respiration, photosynthesis, and other cell processes
What is NAD+ and what is its significance in redox reactions?
- NAD+ gains a H+ to become NADH
- Involved in ATP synthesis
What is NADP+ and its significance in redox reactions?
- NADP+ gains a H+ to become NAPH
- Is not involved in ATP synthesis but is used more directly for photosynthesis and other reactions
What is activation energy?
Energy required for reaction to begin
- Lowers activation energy of reaction
- is a catalyst
- only promotes chemical reactions that could have occurred without it
- Speeds up reaction by lowering activation energy
- is not consumed by reaction
Substance that is binding to the enzyme
Main site of binding for the substrate
An additional chemical component
Region of binding other than the active site
A series of reactions in which adding an enzyme transforms a molecule from one thing to another
When the creation of a product inhibits an earlier reaction in the sequence
Reversible competitive inhibitor
Inhibitor binds to the active site of an enzyme so the substrate cannot bind to it
Reversible non-competitive inhibitor
Inhibitor binds to allosteric site and changes enzyme shape so substrate cannot bind to the active site
Inhibitor permanently destroys enzyme by binding to active site or allosteric site
How do enzymes effect catabolic reactions?
Catabolic enzyme strains substrate so it allows the large molecule to break down into smaller parts
How do enzymes effect anabolic reactions?
Anabolic enzymes orient the substrates so they can be brought together to form larger product
What does activation energy have to do with the inability of many reactions to occur spontaneously?
The # of particle collisions is usually not high enough for reaction to start by itself
What does shape have to do with enzyme function?
shape determines which substrate the enzyme binds with and its function
How does the active site relate to the substrate?
The active site is made in the shape of the specific substrate that it binds with
What role do cofactors play?
- Cofactors are sometimes specific metals the enzyme wants to bind with
- Together with apoenzymes, catalytic activity begins and the enzyme can function
Why do enzymes work best at a certain temperature and pH?
- Reaction is fastest at certain temp and pH
- Temp too low- no reaction
- Temp too high- denature of enzyme
- pH too basic or acidic- denature of enzyme
How are some metabolic pathways controlled by feedback inhibition?
a-----> b -----> c -----> d
If concentration of D is too high, it will signal enzyme 1 to stop making as much of B and eventually it will stop making B altogether
Compare and contrast competitive inhibition and non-competitive inhibition
- Binds to active site
- increasing substrate concentration will relieve inhibition
- does not alter enzyme shape
- only temporary
- ex: malonic acid
- Binds to allosteric site
- Alters enzyme shape so substrate cannot bind to active site
- Increasing substrate concentration will not relieve inhibition
Describe irreversible inhibition
- Enzyme is destroyed when the inhibitor binds to either active site or allosteric site
- most often are poisons
What is the formula for cellular respiration of glucose?
C6H12O6 + 6O2 + 6 H2O--> 6 CO2 + 12 H2O + energy (in chemical bonds of ATP)
What is being oxidized in the glucose formula?
C6H12O6 oxidized to 6 CO2
What is being reduced in the glucose formula?
6O2 reduced to 12 H2O
What goes IN and what comes OUT of glycolysis and Acetyl CoA
What goes IN and what comes OUT of the citric acid cycle?
IN: Acetyl CoA
- OUT: 2 FADH
- 6 NADH
- 2 ATP
- 4 CO2
What goes IN and what comes OUT of electron transport and chemiosmosis?
How are electron transport and H+ ion pumping related?
- The electron pump sends H+ molecules out into the membrane, creating a H+ gradiant
- When the H+ want to come back into the cell, they have to go through ATP synthase where they are attached to NADP+ to make NADPH
- The more H+ = more ATP because more NADPH is being made
What goes IN in alcohol fermentation and what goes OUT?
IN: glucose, NAD+ and NADH
- OUT: 2 ethyl alcohol
- 2 ATP
What goes IN in lactate fermentation and what goes OUT?
What does fermentation contribute to the production of human foods?
fermentation is the basic process involved in making beer, wine, bread dough, the component that makes dough rise, etc.
What is the photosynthesis equation?
6CO2 + 12 H2O -- (light energy/chlorophyll)-> C6H12O6 + 6 O2 + H2O
What is reduced in the equation 6CO2 + 12 H2O -- (light energy/chlorophyll)-> C6H12O6 + 6 O2 + H2O and what is oxidized?
- R: 6 CO2 --> C6H12O6
- O: 12 H2O --> 6 O2
What is the goal of the light reaction?
To convert light energy to chemical energy
What is the function of the photon in the Light Reaction
The photon acts as the high energy particle in the light reaction
What is the function of the H+ ion gradiant and how is it similar to aerobic respiration in an animal cell?
The function of the gradiant sends the H+ ions into ATP synthesis through the thylakoid membrane. It is the same as in the animal cell where the H+ ion is sent to attach to the NADP+ ion
As electron energy is passed among the protein complexes, what is the energy used for?
To transport the H+ ion from the stroma to the thylakoid lumen
What is the overall goal of the Calvin Cycle?
To transform CO2 into sugar
What is the importance of RuBisCo?
It grabs CO2 and combines the molecules in a way that produces sugar
What goes IN to the Calvin Cycle and what comes OUT?
IN: 6 CO2 molecules
OUT: 2 3-carbon molecules that will later be used to build a 6 carbon glucose molecule
NADPH reduction energy and ATP phosphate energy are used to build the intermediates
Critique this often-heard statement: "mitochondria are only found in animal cells, while
chloroplasts are only found in plant cells".
The aerobic respiration equation from mitochondria is mirrored of the equation of photosynthesis
Both require sugar and H+ ions to make the energy that powers their cell, the difference is in how that sugar is acquired.