M Flashcards
Metabolism
2 classes of metabolism
Catabolism
Anabolism
What does catabolism require
Water
Exergonic reactions
Anabolisminvolves whatkind of vxn
Endergonic
ATP abbrev,
Adenosine triphosphate
Catabolism
ATP -) ADP +pi + energy
Anabolism
Catabolism vs anabolism
Collision theory
Explanation of how chemical reactions occur and how certain factors affect the rates of these reactions
Because molecules have mass and are in motion,
Contain energy
► If the energy from a collision is great enough,
it can result in the rearrangement of chemical bonds
Velocity
► The faster an object moves, the more energy it
contains
► More energy means more reacti
Chemical configuration
arrangement of electrons in the molecule
Activation Energy
The amount of energy needed to disrupt an electron configuration so that a reaction occurs
► This number will vary depending on the molecules reacting
► Knowing the activation energy allows us to determine the reaction rate
Reaction Rate
the frequency of collisions containing sufficient energy to start a reaction.
► This is dependent on the number of reactant molecules at or above the activation energy.
► Can be increased by raising the temperature or pressure
Increasing Reaction Rate
Temperature
Pressure
Temp in increasing rxn rate
► Temperature increases reaction rate by providing additional energy to the molecules, speeding them up
► Thus, more collisions with sufficient energy occur
Pressure in Increasing Reaction Rate
Pressure increases reaction rate by forcing the molecules into a smaller space
► Thus, more collisions occur
Enzymes
► Temperature and pressure may speed up a reaction, but are generally not good for cells
► Enzymes lower the activation energy of a reaction
► Enzymes are catalysts which speed up chemical reactions without being altered themselves.
► Enzymes are specific and only catalyze one reaction
Active site
When enzymes bind their substrate in a specific region
They usually exist in the cell in both ______and ______ forms which are dependent on the cell’s environment.
Active and inactive
Factors Affecting Enzyme Activity
Temp
pH
Substrate concentration
Temp does what to enzymes
increase the rate of enzyme activity to a point.
pH alters
Higher or lower than this pH alters the protein structure, stopping function
increase enzyme activity, up until all the enzymes are functioning at maximum
Substrate concentration
Multiple Enzymes Can Work Together
work together to break down the molecule in steps bc there’s a lot of bonds that need to be broken down
Inhibitor types
Competitive
Non competitive
Competitor inhibitor
Fill the active site of the enzyme and compete with substrate for the active site
Non competitive
Bind with another part of the enzyme which changes the shape of the active site.
► aka allosteric inhibition
Feedback Inhibition uses
the enzyme product as an inhibitor
Feedback inhibition is a ______ inhibitor
Non competitive
Feedback inhibitiyion prevents the cell from
wasting resources on more product than it needs.
► Usually occurs in a chain reaction, stopping the first enzyme in the cascade.
Redox Reactions
Couple rxns together
AKA oxidation reduction
In redox reactions
► The molecule that loses electrons is
► The molecule that gains electrons is
oxidized
Reduced
redox reactions used for
photosynthesis, respiration and fermentation to generate energy
Two ways ATP is generated
► Substrate level phosphorylation
► Oxidative phosphorylation
Substrate level phosphorylation
occur when a P is transferred from a phosphorylated compound to ADP.
► C-C-C-P + ADP 🡪 C-C-C + ATP
Oxidative phosphorylation
Electrons are transferred from an organic compound (typically reduced NADH) to a series of electron carriers.
► As the electrons are passed from carrier to carrier, they release energy.
► This energy release is used to attach inorganic phosphate to ADP, generating ATP
Carbohydrate Catabolism
The processing of carbohydrates for the generation of energy:
Carbohydrate Catabolism
Glycolysis
Krebs cycle
Electron transport chain
Glycolysis
The oxidation of glucose to pyruvic acid produces NADH
and ATP
Krebs
Oxidation of acetyl CoA into CO2 produces NADH and FADH2
Electron transport chain
A series of carrier molecules take the NADH and FADH2 from the previous reaction to produce ATP
(30-32 ATP) due to
membranes are not totally impermeable to protons, and not all the glucose molecules make it to the end of glycolysis
38 ATP per
Glucose molecule max
Fermentation
organic compounds can be broken down to release energy
he NADH is regenerated into NAD, so it can be used in glycolysis again
Fermentation 5 factors
- Releases energy from sugars or other organic molecules
- Does not require oxygen
- Does not use the TCA cycle or ETS
- Organic molecule is terminal electron acceptor
- Produces small amounts of energy
Fermentation 2 step program
► Step 1: glycolysis yields 2 pyruvic acids, 2 ATP and 2 NADH molecules
► Step 2: pyruvic acid is converted into end-product, which is organism specifi
Fermentation byproducts
► CO2
► Other gasses
► Alcohol
► Various acids
Lipid catabolism composed of
a glycerol and fatty acid chains that can enter either glycolysis or the acetyl CoA steps
Lipases seperate
the glycerol from the fatty acid
In lipid catabolism
► Glycerol is converted into
► Fatty acids are converted into
glyceraldehyde 3-phosphate
Acetyl Co
Protein Catabolism broken down to reuse
amino acids or converted to enter various points of glycolysis and the TCA cycle
Extracellular proteases and peptidases can break down complex proteins
component amino acids for uptake into the cell
Phototrophs
utilize light energy from the sun to generate chemical energy
Ex. ► Plants, algae, cyanobacteria and purple and green sulfur
Light and Dark Reactions
conversion of CO2, H2O and light into sugars and oxygen is carried out in two steps
Light and Dark Reactions
conversion of CO2, H2O and light into sugars and oxygen is carried out in two steps
Light reactions
In the light reactions, energy from the sun is used to generate ATP and reduce the electron carrier NAD+ into NADH
► This happens in the thylakoids of chloroplasts
