Biochemistry Flashcards
What are the 4 most common elements in organisms? What are the 2 types of compounds?
Elements: hydrogen, oxygen, carbon, nitrogen
Compounds
Covalent: valence electrons shared (C6H12O6 glucose, CO2, H2O, O2)
Ionic: electrons taken or given; has a charge (Na+, H+, K+, OH-, Ca+2, Cl-)
What is the structure of water? What are the cohesive and adhesive properties?
Water: 2 hydrogen, 1 oxygen
Polar covalent bond: hydrogen side is positive, oxygen side is negative
Hydrogen bond from polarity, not as strong as covalent / ionic
Cohesive property: H2O can hold on to other H2Os
Plants bring water from root to leaf against gravity as evaporation pulls it up
Surface tension (water skipper)
Beading (two 2 layers stick and hold bead together)
Adhesive property: sticks to other molecules
Cellulose helps to absorb CO2 for photosynthesis
What are water’s thermal and solvent properties?
Thermal properties
Change of states: solid ice floats on liquid water (weird), otherwise bottoms of lakes would freeze, ice insulates lower water
High latent heat of fusion (Lf; solid → liquid) and latent heat of vaporization (Lv; liquid → gas)
Difficult to change state: takes time to heat, body uses lots of heat to evaporate sweat
High specific heat (heat to raise 1 gram 1°c) because of hydrogen bond
High boiling point: stays liquid over range of temperatures; no place gets to 100°c / 212°f
Stable temperatures for oceans, land near oceans, cells
Solvent properties: universal solvent for polar things, covalent / ionic bonds, proteins with ionic and polar regions
What is the pH scale? How is it regulated?
2H2O → OH- (hydroxide) and H3O+ (hydronium)
pH scale: acidic (0) → neutral (7) → basic / alkaline (14)
Acidic: H3O+ > OH- basic: OH- > H3O+
Each unit on scale is tenfold different in concentration
Water is neutral
Stomach is 2
Most bodily fluid is 6 - 8
Molecule buffers in body minimize pH changes by accepting / donating H3O+ to neutralize
Used between stomach and intestines
What are carbohydrates? What are their functions?
Made of monosaccharides (C6 H12 O6); form rings in water
Monosaccharides: glucose (cell resp), ribose (make DNA / RNA), fructose (fruit, nectar), carbon skeletons take apart for carbon to be used in smaller molecules
Disaccharides: sucrose (transport carbs in plants), lactose (sugar in milk)
Polysaccharides: few to few thousands monos; starch, cellulose, glycogen
Usually soluble, can be hard when long
How are carbs, proteins, and lipids formed?
Condensation synthesis: water formed between OH on one and H on another
Glycosidic linkage leaves oxygen between monosaccharides
Binds glycerol to fatty acid, leaves oxygen
Peptide bond links carboxyl and amine groups
Hydrolysis: add water to break down macromolecules
What are lipids? What are their functions?
Includes fats, phospholipids, steroids
Made of one glycerol (3C chain with hydroxide on one side, otherwise H) and 3 fatty acids (C chain with H, hydrophobic carboxyl group with double bond to O and an OH)
Linked via condensation synthesis
Unsaturated with H: missing H → double bond between Cs → bend (plants, oils)
If saturated, they can stack up (in blood stream), (meat)
Functions: energy storage (2x energy/gram than carbs/protiens, adipose cells, seeds), thermal
insulation
Butyric and palmitic acid, phospholipids (1 acid → phosphate group, 2 acids are tails), steroids
(animal only, 4 rings, cholesterol, testosterone, estradiol)
Insoluble in water
What are proteins? What are their structures?
Made of amino acids: amino, central C with variable R group, carboxyl
20 amino acids, R can be acidic, basic, polar, non polar
Tryptophan, lysine, aspartic acid
Protiens are a few amino acids to > 1000
Function depends on shape
1° primary structure: sequence of amino acids
2° secondary structure: coils from hydrogen bonding between aminos
3° tertiary structure: irregular contortions from bonding R groups (ex hydrophobic parts go inside, disulfide bridges)
4° quaternary structure: only sometimes, many polypeptides form a macromolecule
What are examples and functions of proteins?
Some functions: collagen, vision pigment, spider silk, hormones, antibodies, muscles
Enzyme: catalyze (but not consumed in) reactions; can denature if not in optimal conditions
Immobilized enzymes in industry attach to material to speed reactions
Proteom: all proteins produced by cell/tissue/organ
Fairly soluble unless large or hydrophobic
Describe the structure and function of nucleic acids
DNA: deoxyribonucleic acid; double helix, directs replication and RNA synthesis
RNA: ribonuleic acid; single strand, controls protein synthesis
Made of nucleotides: phosphate group, pentose sugar, nitrogenous base
Form by covalent phosphate-sugar backbone and hydrogen bonds between bases
Soluble
