AnP Lecture - Chapter 2 - Ex1

4 main elements in the body:

C, H, O, N

96% of body weight

Atom: 3 components

Proton (+), neutron, electron (-)

Isotopes

structural variations of elements, same # of protons but different # of neutrons

the atomic # is the same but the mass is different

Atomic weight

the average mass # of all isotope forms of an atom, most abundant isotope

Radioisotopes

heavier, unstable isotopes that decompose into more stable forms; used in research and medicine

*Video: Medical tracers

show the movement of substances in the body, usually use gamma rays to detect them

*Video: Radiotherapy

used to detect and destroy cancer

Molecules

2+ atoms w/ chemical bond: H₂

Compound

2+ different atoms bonded together (H₂O)

Mixtures

2+ physically mixed components, no chemical bond (wine)

Solution

Type of mixture: solute particles are very tiny, do not settle out or scatter light;

homogenous

Colloid

Type of mixture: solute particles do not settle out, are larger than in a solution, and scatter light;

heterogenous

Suspension

Type of mixture: solute particles are very large, settle out, and may scatter light;

heterogenous

Chemically inert

atoms have full valence shells

Chemically reactive

partially empty shells that want to react with other atoms to fill their shells

Ionic bonds

transfer of a valence electron;

cation (+) loses an electron while the anion (-) gains an electron

ex: Na⁺ + Cl^- = NaCl

Covalent bonds:

sharing of 2n valence electrons

ex: CH₄

Hydrogen bonds:

attractive forces between hydrogen and F, O, or N

• weak magnetic forces

• creates surface tension

• a form of intermolecular bond

Anabolic vs Catabolic vs Displacement

Anabolic: synthesis, building

Catabolic: decomposition, breaking down (cats break things)

Displacement: both synth and decomp, usually swapping one or more components with another

Oxidative-reduction reactions (Redox)

OIL - oxidized, it loses electrons = reducing agent

RIG - reduced, it gains electrons = oxidizing agent

Exergonic vs Endergonic Rxns

Exergonic: release energy (EX-crete energy) products have less energy than reactants

Endergonic: absorb energy (ENDER = enter) products have more energy than reactants

Speed of rxns affected by 4 things:

1. temperature: increased temp = increased collisions and force of collisions

2. concentration: increased concentrations = increased collisions

3. particle size: smaller particles = increase of collisions

4. catalysts (enzymes): lower activation energy

Inorganic vs Organic compounds

Inorganic: NO CARBON, water, salts, many acids and bases

Organic: CONTAIN CARBON, macromolecules

5 Important properties of water:

1. high heat capacity: absorb and release heat

2. high heat of vaporization: sweat cools us off because the water absorbs a lot of heat from us to evaporate

3. polar solvent properties: universal solvent

4. reactivity: food + water = hydrolysis rxn

5. cushioning: shock absorption

Salts

ionic compounds that dissociate into anions and cations (electrolytes); vital for homeostasis and electronegative gradients used in many body functions (neuron synapse or muscle contraction)

Acids vs Bases

Acids: proton donors, lower pH

Bases: proton acceptors; higher pH

pH =

-log [H+]

it is logarithmic, each pH unit is a 10-fold difference

ex: the difference between pH 7 and pH 4 is 1000x

Carbohydrates

• Monomer: monosaccharides

• Dimer: disaccharides

• Polymer: polysaccharides

Lipids

• insoluble in water

• triglycerides, phospholipids, steroids, and eicosanoids

• Saturated: solid at room temp, single bonds

• Unsaturated: liquid at room temp, contains double bonds

Nucleic Acids

Phosphodiester bonds

DNA : C = G, A = T ; double stranded helix; deoxyribose sugar, phosphate group, and the base

RNA: C, G, A, U ; single stranded (sometimes double stranded); ribose sugar, phosphate group, and the base

Proteins

Amino acids w/ different R-groups linked together with peptide bonds

Structures: can be fibrous or globular

• Primary: peptide bonds link amino acids

• Secondary: hydrogen bonds form alpha helixes or beta pleated sheets

• Tertiary: R-groups interact and force folding patterns

• Quaternary: 2+ polypeptides interact (ex: haemoglobin has 4 polypeptides interacting)

Enzymes

Globular proteins that are catalysts, lower activation energy to speed up the rate of reactions

Substrate specific via active sites

Usually end in -ase