bio midterm 1 (Purple Pages)

science is to

know

investigative approach to acquiring knowledge by making observations about the natural world, developing explanations and testing those explanations

scientific method

a hypothesis has to be

testable and falsifiable

A failure to falsify a hypothesis does not...

prove that hypothesis

compares an experimental group with a control group

controlled experiment

remains constant

controlled variable

scientifically acceptable and well-substantiated explanation of some part of the natural world, takes many years to establish, supported by exhaustive experimentation, and unlikely to be contradicted later

Scientific Theory

when is observational science used

when its too difficult to establish controlled experiments

basic unit of life

cell

has mass and occupies space, consists of pure elements

matter

a substance that cannot be broken down to other substances by chemical rxs

element

a substance consisting of 2 or more elements in a fixed ratio

compound

Which elements make up 96% of the matter in living organisms?

Hydrogen, Oxygen, Nitrogen, Carbon

What makes living organisms so different?

Different proportion of elements, and the organizations of the molecules

number of protons

atomic number

protons and neutrons

atomic mass

atoms with the same number of protons but different number of neutrons

isotopes

isotopes have the same atomic number but

different atomic mass

unstable isotopes that decay and release energy

radioisotopes

rate of decay in an isotope is

constant

the amount of time for it to break down, leaving half

half life

a substance containing radioisotopes that is used to measure the speed of a chemical processes and/or movement of speed

radioactive tracers

Why was there a global radioisotope shortage between 2007-2010?

Shut down of Chalk river in Canada, Produces 30-40% of world supply

the number of electrons is equal to the number of

protons

electron are in

orbitals

Valence electrons determine an atom's

reactivity

4 main types of chemical bonds

a. Ionic

b. Covalent

c. Hydrogen

d. van der Waals Forces

transfer of electron from one atom to another

ionic (intra)

sharing of a pair of valence electrons (have a distinct 3D form)

covalent bond (intra)

structure is related to

function

measure of an atom's attraction for electrons in a covalent bond

electronegativity

unequal sharing of electrons

polar covalent bond

Partial positive charge of H atom are attracted to partial negative charge of nearby atoms, weaker than covalent and ionic bonds

Hydrogen bonding (intermolecular)

•Weaker than hydrogen bonds

•Develop between nonpolar molecules

•Constant motion of electrons causes them to accumulate by chance on one region of molecule

van der Waals forces (inter)

water is more dense than

ice

the structure of water gives it a ______ and allows for _________

high specific hear capacity , attraction between water molecules (cohesion)

•Water molecules surround polar molecules and ions, allows for separation of molecules

Hydration Shell

proton donor

acid

proton acceptor

base

•Controls pH by absorbing or releasing H+

• Most are weak acids or weak bases

Buffers

What controls the pH of our blood?

Carbonic acid

Living matter are all composed of carbon compounds

organic

How many covalent bonds can carbon form?

4, this tetravalence makes large complex molecules possible

•Vary in length and shape

• molecules where carbon is bound only to hydrogen

hydrocarbons

single carbon bond

-ane

double carbon bond

ene

triple carbon bond

-yne

•- reactive groups

- enter into biological reactions

- bind to carbon

functional groups

1.(-OH)

hydroxyl

2.(-C=O)

Carbonyl

3.(-COOH)

Carboxyl

4.(-NH2)

Animo

5.(-PO42-)

Phosphate

6. (-SH)

Sulfhydryl

dehydration (remove water to form a bond)

synthesis of a polymer

-hydrolysis reaction (add water to break a bond)

breakdown of a polymer

Sugars and the polymers of sugars (fuel and building material)

Carbohydrates

•Multiples of CH2O (1:2:1) (a-glucose easier for animal cells to breakdown)

monosaccharides

Isomers of Monosaccharides have the same chemical formula, but different

molecular structure and function

Enantiomers

isomers that are mirror images of each other

difference between an aldehyde and a ketone

Different position of carbonyl group

Covalent bond in between Disaccharides

glycosidic linkage

2 glucose

maltose

glucose and fructose

sucrose

glucose and galactose

lactose

amylose (alpha 1-4) is

unbranched

glycogen is

branched

has a beta 1-4 linkage with H-bonds

Cellulose

has beta linkages and N-groups

chitin

protein functions

- Structural support

- Storage

- Transport

- Enzymes in reactions

- Cellular communications

- Movement

How many different human proteins?

over 100 000

polymers amino acids

polypeptides

How many different types of amino acids?

20

carbon in a protein is called a

alpha protein

Alanine (Ala, A)

Nonpolar

Valine (Val, V)

nonpolar

Leucine ( Leu, L)

nonpolar

Isoleucine (Ile, I)

nonpolar

Glycine (Gly, G)

nonpolar

cystine (Cys, C)

Nonpolar, can b polar under a certain pH

Phenylalanine (Phe, F)

Nonpolar

Tryptophan, Trp, W

nonpolar

Methionine, Met, M

nonpolar

Proline, Pro, P

nonpolar

Serine, Ser, S

polar, uncharged

Threonine, Thr, T

polar, uncharged

Tyrosine, Tyr, Y

polar, uncharged

Asparagine, Asn, N

polar, uncharged

Glutamine, Gln, Q

polar, uncharged

Aspartic acid, Asp, D

negatively charged polar

Glutamic acid, Glu, E

negatively charged polar

Lysine, Lys, K

Polar basic, positive charge

Arginine, Arg, R

Polar basic, positive charge

Histidine, His, H

Polar basic, positive charge

•Covalent bond

•Dehydration

•Amino acid added only to carboxyl end

peptides

what kind of bonds do proteins have

peptide bonds

linear sequence of amino acids

primary structure

•H-bonds between amino acids

•O and H of backbone

folds into

-Alpha helix

-Beta pleated sheets

secondary structure

•All types of bonds between R groups

form a 3D shape and Function

tertiary structure

•≥ 2 polypeptides

•All types of bonds

Quaternary structure