What do enzymes do
They’re biological catalysts, mostly proteins, that speed up chemical reactions without being consumed or changing the product of the reaction
Controls all cellular activity
4000+ different enzymes in the body
Each enzyme has a unique 3D shape which determines which reaction they catalyze
What are substrates
Enzymes briefly bind to substrates which are specific reactants and releases after the chemical reaction
substrates interact with enzymes at the active site which is a pocket or groove
Induced fit model
Model of enzymes activity that describes how an enzyme will change shape to better accommodate a substrate
Exothermic vs endothermic
Exo - also known as exergonic reactions, releases energy from bonds (product molecules = smaller than reactants) basically breaking down
Endo - also known as endergonic reactions, stores energy in bonds (product molecules = bigger than reactants) putting together
Cofactor and coenzyme
They improve the efficiency of enzymes
Cofactors are a non protein group that binds very precisely to an enzyme (often metals) they’re absolutely essential
Coenzymes are an organic molecule that acts as a cofactor of an enzyme
They shuttle molecules from one enzymes to another in cascading chemical reactions
One very important one is nicotinamide dinucleotide (NAD+) which fuels the process to make ATP
The four factors that affect enzyme function
Enzyme and substrate concentration
Allosteric sites
Ph impacts
Temperature
Enzyme and substrate concentration
They need to have a 1:1 ratio otherwise the rate of the reaction is limited, whether there’s too much of one or not enough of the other
Competitive vs non competitive inhibitors
Competitive - a competitor substance binds to the active site where the substrate should which blocks enzyme activity
Noncompetitive - molecules will bind to other parts of the enzyme but don’t directly block the active site, but it stills impacts the reactions
Enzyme inhibitors
Lower the rate of catalyzation in a reaction
Can bond reversibly or irreversibly
Irreversibly can be toxic to cells and kill them
Allosteric sites and regulation
A binding site on the enzyme that binds regulatory molecules to regulate enzyme activity
Allosteric regulation is regulating one site of a protein to another site on the same protein
Changes the shape of the enzyme which affects active site binding
pH impacts
Enzymes have optimal ph’s to function in
If it’s off balance, the enzyme can’t function
Like how amalyze works better in an acidic environment to break down carbs
Once outside of the optimal range, the effectivity quickly drops to zero
Temperature
As temperature increases the rate of enzyme catalyzed reaction increases until the enzyme begins to denature and then it quickly drops to zero
If not at an optimal temp, the active site will change
Cell theory
All living organisms made up of 1+ cells
All cells come from cells
Cells are basic building block of life
Organelles
Internal structures of a cell that have specialized internal functions
Cytosol vs cytoplasm
Cytosol is the fluid portion of the cell
Cytoplasm is all components in a cell except nucleus
Don’t use cytoplasm
Plasma membrane
Surrounds EACH organelle and the cell itself
Controls the amount and type of substances that can go in or out of the cell / organelle
Fluid mosaic model
Idea that a biological membrane consists of fluid phospholipid bilayer in which proteins are embedded and float freely
Nucleus
Contains almost all DNA in cell
composed of nuclear envelope and nucleolus
Protects DNA from harmful things like metabolic activity that could damage it
Nuclear envelope vs nucleolus
Nuclear envelope - double membrane with two lipid bolsters surrounding the nucleus
Proteins in the envelope transports various molecules
Nucleolus - contains nucleoplasm where subunits of ribosomes are assembled from proteins and DNA
Endomembrane sustem
Group of interacting organelles
Between nucleus and plasma membrane
Makes lipids, enzymes, proteins for secretion and insertion into cell membranes
Composed of both ERs, Golgi body and vesicles
Rough vs smooth ER
Extension of nuclear envelope
Rough contains ribosomes to synthesize proteins
Smooth gets left over proteins to make enzymes to break down other macros
Vesicles
Buds off rough ER to carry some synthesized proteins to Golgi body
Vacuoles are a type of vesicle
Golgi body
Modifies proteins into their final form and transports them to plasma membrane or lysosomes
Final form (attaches phosphate groups or sugars)
Mitochondria
Produces ATP which is a coenzyme
Takes more energy than any other metabolic process
Can have 1000+ in every cell
2 membrane
Has their own DNA and ribosomes
