Biochemistry Flashcards
Biochemistry
- the study of chemical composition and reactions of living matter
- all chemicals either organic or inorganic
Classes of chemical compounds
Inorganic: water, salts, many acids & bases(No carbon)
Organic: Carbs, fats, proteins, nucleic acids(Yes Carbon)
Properties of water
- High heat capacity
- High heat of Vaporization
- Polar solvent properties: dissolves and dissociates ionic substances, forms hydration layers around large charged molecules, body’s major transport medium
- Reactivity
- Cushioning: Protects organs from physical trauma
Salts
- ionic compounds. that dissociate into ions in water
- contraindications other than H and anions other an OH
- common salts: NaCl, CaCO3, KCl
pH
- relative free [H] of a solution measures on pH scale
- as free [H] increases: acidity increases, pH decreses
- as free[H] decreases: alkalinity increases, pH increases
- ph scale 0-14
- Acid: 0-6.99
- Neutral: 7 ( pure water)
- Basic: 7.01-14
Important acids
HCL(Hydrochloric Acid), HC2H3O2(Acetic Acid), H2CO3(Carbonic Acid)
Important bases
Bicarbonate ion(HCO3–) and Ammonia(NH3)
Acids and bases
- both are elctonegative
- Acids: proton donors, release H
- Bases: Proton acceptor, take up H from solution
Neutralization
- Results from mixing acids and base
- Displacement reactions occur forming water and a salt
Buffers
- acidity reflects only free H in solution
- buffers resist abrupt and large swings in pH
- covert strong acids or bases into weak ones
- carbonic acid-bicarbonate system,(important buffer system of blood)
Arrhenius equation
ln(k) = ln(A)-Ea/RT
k = rate constant of reaction
A = Arrhenius factor
Ea = activation energy
R = gas constant
- used to analyze the effects of temperature on the rates of chemical reactions
Use of Chemical by cells
- Chemical reactions: when atoms combine or change partners, necessary to maintoan order in the cell
- Follows the rule of thermodynamics: open system = can exchange matter and energy with surroundings
Free Energy
∆G < 0 -> spontaneous
∆G = 0 -> reaction is at equilibrium
∆G > 0 -> opposite reaction occurs spontaneously
ATP
*Chemical energy in glucose captured in this important molecule
* Directly powers chemical reactions in cells
* Energy form immediately useable by all body cells
* StructureofATP
* Adenine-containing RNA nucleotide with two additional phosphate groups
Function of ATP
Phosphorylation: terminal phosphonates are enzymatically transferred to and energize other molecules
Organic compounds
-Crabs, lipids, proteins, nucleic acids
-polymers, chains of polymers become monomers
Nucleic Acids
-deoxyribonucleic acids(DNA) and ribonucleic acids(RNA)
- contains: C,O,H,N,P
DNA
- Utilizes four nitrogen bases:
- Purines:Adenine(A),Guanine(G)
- Pyrimidines:Cytosine(C),and thymine(T)
- Base-pair-rule–each base pairs with its complementary base
- A always pairs with T;G always pairs with C
- Double-stranded helical molecule(double helix) in the cell nucleus
- Pentose sugar is deoxyribose
- Provides instructions for protein synthesis
- Replicates before cell division ensuring genetic continuity
RNA
- Four bases: A, U, G, C
- Pentose sugar is ribose
- Single-strand molecules mostly active outside the nucleus
- Three main varieties of RNA carry out the DNA orders for protein synthesis
- mRNA, tRNA, rRNA
Carbs
*sugars and starches
*polymers
*Contains C, H, O
*Three classes: Monosaccharides, Disaccharides, Polysaccharides
*Function: source of cellular fuel, structural molecules
Monosaccharides
- Simple sugars containing three to seven C atoms
- Monomers of carbs
- Important monosaccharides
- pentose sugars
- hexose sugars
Disaccharides
- Double sugar
- Too long to pass through cell membrane
- Important disaccharides: sucrose, maltose, lactose
Polysaccharides
*Polymers of monosaccharides
*important polysaccharides: Starch and Glycogen
*Not very Soluble
Lipids
*Contains C, H, O and same P
* Insoluble in water
* Main types: Triglycerides, Phospholipids, Steroids, Eicosanoids