unit 1: chemistry of life

science (features)

testable; repeatable; fallible

scientific method

make observations → form questions → create hypotheses → test hypotheses → run experiment(s) → analyze results → make conclusion / theory

hypothesis

testable solution; possible answer to a question

null hypothesis (H₀)

no effect; nothing will change

alternative hypothesis (Hₐ)

observable effect; something will change

independent variable (IV)

altered variable

dependent variable (DV)

variable expected to change in response to other variable

control group

comparison group; only independent variable changes

negative control

used to determine failure or no change

positive control

used to determine success or change

ontology

the nature of being; does a characteristic define or diagnose something?

epistemology

study of knowledge; when do you know something?

parsimony

most probable solution has the least number of assumptions

induction

looks at evidence that supports hypothesis

deduction

looks at evidence that rejects hypothesis

electronegativity

tendency to acquire electrons

oxygen

very electronegative

hydrogen bonds

weak electrostatic bonds between water molecules; easily separate and rejoin

cohesion

attraction to self / like molecules

adhesion

attraction to other / differing molecules

hydrophilic

water loving

hydrophobic

water fearing; non-polar

capillary action

water moves up tube against gravity; due to cohesion + adhesion

carbon

4 valence electrons; 4 covalent bonds; strong cohesion

functional group

part of a molecule

hydrocarbons

compound made of carbon and hydrogen

acidic

can release H⁺; turns OH to O⁻

basic

can collect H⁺; turns N to N⁻

hydroxyl (structure)

R to OH; polar

sulfhydryl (structure)

R to SH; polar

methyl (structure)

R to CH₃; non-polar

carbonyl (structure)

C double bonded to O; polar

carboxyl (structure)

C double bonded to O; C to OH; acidic

amino (structure)

N with 3 single bonds; add H⁺, becomes N⁻; basic

phosphate

phosphorus bonded to OH; acidic

polymers

molecule consisting of repeating monomers

amino acid

C bonded to amino, carboxyl, hydrogen, and R (determines acid type)

hydrolysis

add water; destroy macromolecules; release amino acids

condensation

dehydration; destroy macromolecules; release amino acids

carbohydrates (mono)

monosaccharides

carbohydrates (poly)

polysaccharide

carbohydrates (bond)

glycosidic

carbohydrates (elements)

CHO

proteins (mono)

amino acids

proteins (poly)

polypeptide

proteins (bond)

peptide

proteins (elements)

CHON(S)

nucleic acid (mono)

nucleotide

nucleic acid (poly)

DNA; RNA

nucleic acid (bond)

phosphodiester

nucleic acid (elements)

CHONP

lipids (elements)

CHO(P)

carbohydrates (functions)

energy; structure; cell recognition

isomers

compounds with same chemical formula but different arrangements

enantiomers

isomers; mirror images, not identical

diastereomers

isomers; non-mirror images

fructose

monosaccharide; ketose; six carbon

disaccharides

two monosaccharides linked by glycosidic bond

maltose

glucose + glucose

lactose

glucose + galactose

sucrose

glucose + fructose

α 1-4 glycosidic bond

alpha ring form; bond between carbon 1 & 4

β 1-4 glycosidic bond

beta ring form; bond between carbon 1 & 4

α 1-6 glycosidic bond

alpha ring form; bond between carbon 1 & 6

α ring form

glucose ring; hydrogen on top of hydroxyl

polysaccharides

long chain of monosaccharides

starch

plant energy storage; glucose; mostly α 1-4 glycosidic bonds (amylose); α 1-6 glycosidic bond every 24-30 bonds (amylopectin)

glycogen

animal energy storage; glucose; mostly α 1-4 glycosidic bonds; α 1-6 glycosidic bond every 8-12 bonds

cellulose

plant fiber; β 1-4 glycosidic bond

chitin

used for arthropod exoskeletons and fungi cell walls; no glucose

lipids (functions)

energy storage; structure; communication; protection

fatty acid

long hydrocarbon chain with a carboxyl group

unsaturated fatty acid

double bonded hydrocarbon; more liquidy

saturated fatty acid

no double bonds; hydrocarbon; more solid

cis fats

have kinks; more common in nature; hydrogens on same side of double bond

trans fats

not common in nature; hydrogens on oposite sides of double bond

triglycerides

glycerol + 3 fatty acids

phospholipids

glycerol + 2 fatty acids + phosphate head

steroids

lipids with ONLY 4 rings

proteins (functions)

structure; transport; enzymes; communication; storage; movement; defense

n-terminal

start of polypeptide

c-terminal

end of polypeptide

primary structure

order of amino acids in a polypeptide

secondary structure

local folding in regions of polypeptide; α-helix and β pleated sheet; hydrogen bonds

tertiary structure

unique 3D structure of polypeptide; determined by R group interactions

quaternary structure

combination of multiple polypeptides (subunits); polar / charged amino acids on outside

amino acid groups

positively charged (basic) R group; negatively charged (acidic) R group; uncharged polar R group; uncharged nonpolar R group

protein mutation

likely benign if in-group; likely pathogenic if out-group

nucleic acids (functions)

information; protein synthesis; regulation; energy; structure

dna (function)

nucleic acid; carries genetic information

dna (location)

nucleic acid; in nucleus

dna (stability)

nucleic acid; more stable

dna (structure)

double helix

dna (sugar)

deoxyribose

dna (pyrimidines)

cytosine, thymine

rna (function)

nucleic acid; involved in protein synthesis

rna (location)

nucleic acid; leaves the nucleus

rna (stability)

nucleic acid; less stable

rna (structure)

single stranded

rna (sugar)

ribose