What kind of studies during the early 20th century showed incredible commonality in different organisms?
Studies into the metabolic pathways
What's an example of some commonalities in different organisms in metabolic pathways?
A muscle fiber and a yeast cell have the same 10 enzymes involved in the breakdown of glucose
What is something a muscle fiber and a yeast cell have in common?
The same 10 enzymes are involved in the breakdown of glucose
Biochemistry has a critical role in which fields?
Medicine
Pathology
Nutrition
Environment
What field is biotechnology used in?
Pharmeceutical industry
New fuels
What kinds of things can happen when just one biomolecule malfunctions?
Leads to disorders like cancer, sickle cell anemia, thalassemia, cystic fibrosis, etc.
What is Ras?
A small G protein
What happens when Ras malfunctions?
Cancer
What is P53?
Tumor suppressor gene
What happens when P53 malfunctions?
Cancer
What happens when hemoglobin malfunctions?
Sickle cell anemia
Thalassemia
What is CFTR?
A Cl- channel
What happens when CFTR malfunctions?
Cystic fibrosis
What is Cell Theory?
Cells are the basic units of structure, function, and reproduction in living organisms
What is the difference between Eukaryotic and Prokaryotic cells?
Eukaryotic cells contain membrane-bound organelles, including a nucleus; can be single or multi celled
Prokaryotic cells do not contain a nucleus or any other membrane-bound organelle
What's an example of a prokaryote?
Bacteria
What is the difference between plant and animal cells?
Plant cells: Possess chloroplasts, cellulosic cell wall, "cell plate" and protoplasmic fibers during division, large central vacuole; Starch is stored food
Animal cells: No cell wall or chloroplasts; Possess very small vacuoles, centrioles/centrosomes, "cleavage furrow" during cell division, lysosome; Glycogen is stored food
What do chloroplasts do in plant cells?
Perform photosynthesis
What forms the protoplasmic fibers during cell divison in plants?
Spindle apparatus
What happens during cell division in plants?
Daughter cells are separated into two by formation of cell plate
Cell plate grows from center towards periphery in protoplasm btwn two daughter cells
What happens during cell division in animals?
Cleavage furrow separates daughter cells by constrictions growing from periphery towards center
What is the role of centrioles in animals?
Involved in the formation of the spindle apparatus during cell division
What is the molecular hierarchy of structure?
The cell and its organelles
Supramolecular complexes
Macromolecules
Monomeric units
What are some supramolecular molecules?
Chromatin
Plasma membrane
Cell wall
What is the molecular hierarchy of chromatin?
Chromatin
DNA
Nucleotides
What is the molecular hierarchy of the plasma membrane?
Plasma membrane
Protein
Amino acids
What is the molecular hierarchy of the cell wall?
Cell wall
Cellulose
Sugars
What kind of interactions/bonds are formed btwn monomeric units to make macromolecules?
Covalent bonds
What kind of interactions/bonds are formed btwn macromolecules to make supramolecular complexes?
Non-covalent interactions
Why is carbon such an incredible atom?
Can form single bonds with hydrogen atoms
Can form single and double bonds with oxygen and nitrogen atoms
Can form stable single bonds with other carbon atoms and also form double and triple bonds
What are the different functional groups?
Alcohols with Hydroxyl groups
Amines with amino groups
Aldehyde and ketones with carbonyl groups
Carboxylic acids with carboxyl groups
What is stereochemistry?
Arrangement of the molecule's atoms in 3D space
What allows for the existance of stereoisomers?
Carbon
What does stereoisomer mean?
Can't be interconverted without breaking a covalent bond
What are the sources of stereoisomers?
Chiral centers
Double bonds
What about chiral centers makes stereoisomers?
Asymmetric C
What about double bonds makes stereoisomers?
Geometric isomers
All interactions between biomolecules are __________?
Stereospecific
Describe geometric isomers
Differ in the arrangement of their groups with respect to the non-rotating double bond
Will have different molecular interactions
What is an example of stereoisomers b/c of geometry?
Maleic acid (cis)
Fumaric acid (trans)
What kind of conversion of retinal allows for vision?
Light conversion from cis to trans
What are chiral centers?
Corresponds to asymmetric carbons
What is an asymmetric carbon?
A carbon with 4 different substituents
How many stereoisomers can form from a molecule with 1 chiral carbon?
2 stereoisomers
How many stereoisomers form based on the number of chiral carbons?
2n stereoisomers
(n = number of chiral centers)
What are enantiomers?
Stereoisomers that are mirror images of each other
What are diastereomers?
Stereoisomers that are not mirror images of each other
What kind of effects do enantiomers have?
Different biological effects
What is citalopram?
Prescription medication to treat major depression
SSRI drug
What is the active form of the citalopram enantiomer?
Escitalopram
What was thalidomide and what was it taken for?
One enantiomer was a mild sedative
Prescribed for anxiety and other disorders
What was wrong with the thalidomide product?
Sold the racemic mixture
Not tested in pregnant women
"inactive" enantiomer had teratogenic properties
Lead to birth defects
What is the equilibrium constant?
Keq
The tendency of a chemical reaction to go to completion
How is the equilibrium constant written as an equation if the chemical equation is A + B ⇆ C + D?
Keq = [C][D]/[A][B]
Product concentrations/Reactant concentrations
What are redox reactions?
All chemical reactions in which atoms have their oxidation state changed
There is a transfer of electrons between species
How is the oxidation state of atoms changed?
There is a transfer of electrons
What is oxidation?
Loss of electrons
Increase in oxidation state
Electrons on product side
What is reduction?
Gain in electrons
Decrease in oxidation state
Electrons on reactant side
What happens during respiration?
Energy is obtained from glucose in an oxidative process
Glucose is oxidized several times to slowly extract the energy in its chemical bonds
Eventually we end up with CO2 and H2O (and we obtain ATP)
What's an example of respiration?
C6H12O6 + 6O2 → 6CO2 + 6H2O
What happens during photosynthesis?
Sugars are synthesized
Reduction of carbon dioxide into sugars
Oxidation of water into oxygen
Light provides energy
What is the 1st law of thermodynamics?
The total amt of ENERGY in the universe remains CONSTANT
Although the FORM of energy may change
What is the 2nd law of thermodynamics?
The total entropy of the universe is continually increasing
(the universe tends towards ever-greater disorder)
What is Gibbs free energy?
ΔG
A measure of the amount f mechanical work that can be obtained from a system
What is the Gibbs free energy equation for a reaction occurring at constant temperature?
ΔG = ΔH - TΔS
What does ΔH stand for?
The change in the number and type of chemical bonds that take place in the reaction
A measure of heat content
What does ΔS stand for?
The change in the system's randomness
What is entropy?
The randomness or disorder of the components of a chemical system (S)
What are examples of how we can increase entropy?
If a chemical reaction increases the number of free molecules
If a solid is converted to a liquid, or a liquid to gas
What are examples of how we can decrease entropy?
Organizing nucleotides into a coherent sequence of DNA
Why does organizing nucleotides into a coherent sequence of DNA decrease entropy?
Several small molecules become a single molecule
There is an order to the molecules, which is a form of information
(T/F) Breaking a bond is an endothermic process.
True
Energy goes into breaking it
For a given temperature and pressure, what happens if ΔG < 0?
Energy is released
Exergonic process
For a given temperature and pressure, what happens if ΔG > 0?
Energy is absorbed
Endergonic process
For a given temperature and pressure, what happens if ΔG = 0?
The reaction is at equilibrium
What kind of process takes place if energy is absorbed?
Endergonic process
What kind of process takes place if energy is released?
Exergonic process
In the body, why do most endergonic reactions occur?
Because they are COUPLED to an exergonic reaction
In the body, why are most endergonic reactions coupled to an exergonic reaction?
So that the total change in free energy is negative
In biological reactions, what is the usual source of energy?
The energy released by breaking the phosphoanhydride bonds in ATP and GTP
Energy is released by breaking what kind of bonds in ATP and GTP?
Phosphoanhydride bonds
What does ΔG depend on?
Many factors
Concentration of substrates and products
What is Standard free energy?
ΔG°
The ΔG of a reaction under very specific (standard) conditions
What are standard conditions?
[S] = [P] = 1 M
T = 25° C
P = 1 atm
How is ΔG° defined?
The change in energy occurring when a reaction, under standard conditions, proceeds from start to equilibrium
How can you show that the equilibrium constant and Gibbs are related?
ΔG = ΔG° + RT*ln([C][D]/[A][B])
In equilibrium- ΔG = 0
New equation- ΔG° = -RT*ln(Keq)
What are catalysts?
Compound that increases the rate of a chemical reaction
Lower the activation of free energy ΔG
Do not alter ΔG
What do enzymatic catalysis offer?
Acceleration under mild conditions
High specificity
Possibility for regulation
What is sickel cell anemia?
A biochemical disease
Characterized by red blood cells acquiring abnormal, rigid, sickle shape
Found in 1 out of 600 African Americans
No sign till 6 months
Life expectancy is reduced
What is hemoglobin?
Protein that transports oxygen in blood
What is hemoglobin composed of?
4 polypeptide chains- 2 alpha and 2 beta chains
Each contains a heme group
What is a heme group?
Contains one iron atom that can bind one oxygen molecule
What is the most common form of hemoglobin?
HbA
What is anemia?
Reduction in the oxygen transporting capacity of blood
What causes sickle cell anemia?
Point mutation- Change in one of the 287 amino acids in the beta chain
Glutamic acid --> Valine (HbS)
Abnormal hemoglobin crystalizes (forms a chain) when blood Oxygen levels are low
Causes sickle shape in RBC's
How is a heterozyglous mutation of hemoglobin beneficial?
Provides resistance against malaria
How much of the oxygen in blood is bound to and transported by hemoglobin?
98%
What was one of the first proteins to be crystalized?
