A type of reaction that releases energy, usually ATP and heat
What is endergonic?
A type of reaction that uses more energy than is released, uses ATP and releases some heat.
What are Oxidation-reduction reactions?
electron transfer from electron donor to electron acceptor
necessary in many metabolic pathways
reactions always occur simultaneously
cells use "electron carriers" to carry electrons
What are the electron carriers?
What is ATP?
Energy source of the cell
How is ATP produced?
organisms break down nutrients to release energy
where is the energy stored at in ATP?
In the high energy phosphate bonds
What is Phosphorlyation?
where an inorganic phosphate is added to a substrate (ADP-->ATP)
how are catabloism and anabolism involved with ATP?
Catabolism: stores energy in ATP
Anabolism: releases energy from ATP by breaking bonds
What are enzymes?
They are Proteins and biological Catalysts that can be used over and over again.
What are the 2 major things enzymes do in a chemical reaction?
1) speed up metabloic reactions
2) lower the energy needed for the reaction to occur
What is enzyme-substrate specificity?
Where only certain substrates will fit into certain enzymes
What is a substrate?
A molecule that is being Metabolized
3 major steps in enzyme action.
1) Substrate binds to the enzyme
2) after bound, the enzyme changes shape
3) the substrates are then released, and enzyme returned to original shape.
What is the "Induced fit model"?
How enzymes change shape slightly after the substrate bonds to it.
What are the products of enzyme activity used for?
The cell uses the products for metabloic activities.
What are cofactors? Examples?
they are helpers to the enzymes
Inorganic: iron, magnesium, zinc, copper
What are Coenzymes? Example?
Organic helpers to the enzyme
What 5 things affect enzyme activity?
1) Temperature: increase temp, speed up act.
2) pH: most places have 6.4
3) amount of Enzyme
4) amount of substrate
5) presence of inhibitors
What is denaturation?
Where the enzmye changes shape
what is the sturation point?
Where the amount of substrate is at its limit inside the cell.
What is an inhibitor?
A substance that blocks an enzyme's active sites.
Fit into the enzyme active site
bind permanently or reversibly
If increased substrate concentration it can push out the inhibitor
binds to allosteric site
alters shape of active site so subrate doesn't match.
What is allosteric activation?
Binds to allosteric site and changes the shape to ALLOW the enzyme to bind.
What is Feedback inhibition?
End product of metabloic activity is an allosteric inhibitor of enzyme in a series of reactions.
What is a Ribozyme?
3D RNA molecule that can catalyze a chemical reaction
Most are rare in a cell
Technically, part of ribosome is a ribozyme (amino acids are put together to make protein w/o other catalysts)
What is carbohydrate catabolism?
Using carbohydrates to obtain energy for metabolic activities.
What two ways are carb. catabolized?
1) Cellular respiration: Glucose --> CO2 + H2O ( for ATP)
2) Fermentation: Glucose to organic waste products
Begin with Glycolysis
What is cellular respiration? Goal?
Extracting energy from molecules
goal: release as much ATP as possible
involve NAD+ & FAD
Formula for Cellular Respiration with presence of Oxygen?
Aerobic Respiration C6H12O6 + 6O2--> 6CO2 + 6H2O + ATP
What are the steps for Cellular respiration?
2) Transition/Acetyl-CoA synthesis
3) Krebs Cycle
4) Electron Transport chain (ETC)
Step 1: Glycolysis
Occurs in Cytosol
Glucose is broken down into pyruvate
ATP is made
Electrons are given to NAD+ --> NADH
2 ATP used, 4 ATP made= 2 Net ATP (euk. and prok.)
Electrons given to 2 NAD+--> 2 NADH
Step 2: Transition/Acetyl-CoA synthesis
2 NAD+ get electrons --> NADH
2 Acetlyl-CoA are made
In Euk.:inside Mitochondria
In Prok. Out in the Cytosol
What are Precursor Metabolites?
Any of the 12 molecules generated by a catabolic pathway and essential to the synthesis of organic macromolecules in a cell
What is a Hypothesis?
A description of nature used to explain observations. Hypothesis have little or no supporting experimental evidence and/or observarions but can be used to predict the outcome of experiments. It is a tentative explanation.
What is a prediction?
Expected outcome of an experiment. It can be written in the following format (If.....Then....).
What is an experiment?
Used to test the hypothesis, theories and laws.
Group used for comparison in an experiment. Usually treatment group where the independent variable is not applied.
Group that is being manipulated. Treatment group to which the independent variable has been applied.
The variable that the investigator manipulates or changes in an experiment.
the variable that changes in an expeiment as a result of manipulating the IV. the result of the experiment that s observed.
The variables that the experiment keeps constant.
Why is replication important?
the more data collected, the more accurate the results will be.
Stage 3:Krebs Cycle
2 ATP made
4 CO2 released
Stage 4: ETC (Electron transport chain)
most significant production of ATP
moves H Ions across concentration gradient to produce ATP
EUK= Cristae of Mitochondria, 32 ATP made (36 total)
PROK= Cytoplamsic membrane, 34 ATP made (38 total)