Bio Chapter 2

Element

found in all materials of nature, only has one type of atom

atoms

basic unit of matter, contains Protons (+), Neutrons, (neutral), and Electrons (-)

Valence shell

outer most shell

The ___ the electrons are, the ___ ____ it has

father, more energy

the max amount an electron can have on the first shell is

2

the max amount an electron can have on the outer shells are

8

True or False: Can only fill next shell when shells are all full (either 2 or 8)

True

molecule

2 or more atoms linked by chemical bonds

singe bond

2 E shared

double bond

4 E shared

triple bond

6 E shared

nonpolar covalent

when atoms equally share their electrons with same electronegative atoms (methane/CH4)

polar covalent

when atoms unequally share electrons with atoms with different electronegativities (H2O; O is partially neg bc E is drawn to it and H is partially positive bc E is far away)

Oxygen is very ___, which means _____

Electronegative, electrons are attracted to it

Ionic bonds

Strongest bond. atom donates/gains E because electronegativites are very different. When one atom donates an E it has a cation (pos) charge and the other one, with an E now, has a anion (neg) charge

Hydrogen bond

weakest bond. partially positive hydrogen atoms interact with partially negative atoms of a different molecule. constantly breaking and reforming.

Hydrophobic

molecules that hate water (oil)

Hydrophilic

molecules that love water (salt)

pH scale

0-14

in pH scale, 0-6 is ____

acidic

in pH scale, 8-14 is ____

basic

in pH scale, 7 is ____

neutral

Dehydration synthesis

removing water to create bonds, adding ATP Energy

Hydrolysis

adding water to break bond

Cohesion

hydrogen bond ONLY between water molecules (water droplets)

Adhesion

Hydrogen bond between water molecules and other atoms

Hydrogen bonds ___ when temp ____

break, changes

4 Major chemicals

Carbon, Hydrogen, Nitrogen, Oxygen

functional groups

amino, carboxyl, carbonyl, hydroxyl, methyl, phosphate

Carboxyl

COOH

Amino

NH2

Carbonyl

C=0

Hydroxyl

OH

Methyl

CH3

Phosphate

OPO3H2

organic molecules

proteins, nucleic acid, lipids, carbohydrates

proteins (polypeptides)

does most work, catalysts for chemical reactions, structural support

protein is a ____ formed by amino acid monomers liked by ____

polymer, peptides

Nucleic Acid

encodes and transmits genetic info (DNA)

nucleic acid is a ____ and is made of _____

Polymer, phosphate bonds

Nuclei acids are polymers, and their monomers are_____ and are linked together with _____

Nucleotides , phosphodiester bonds

DNA

double helix, thymine, adeline, guamine

RNA

single strand, uracil, guamine, adeine

pyrmide

1 ring, CTU

Purine

2 rings, G, A

Carbohydrates

structural support, provides energy

carb is a ___ and its monomer is a _____, linked with ______

polymer, monosaccharide, glycosidic bonds

Monosaccharide formula

Cn H2n On

Lipids

make up cell membrane, store energy, help with communication in the cell

Lipids are ___ a _____ and are _____

not, polymer, hydrophobic

3 types of lipids

Triglycerides, steroids, phospholipids

Triglycerides contain

glycerol and fatty acids

fatty acids in TG

long chain of carbon with carboxyl (COOH) group at the end

Saturated FA

single bond carbon, max # of hydrogens, solid at room temperature, straight structure (eg is butter)

Unsaturated FA

double bond carbon, less max # hydrogen, bent structure, liquid at room temperature (eg olive oil)

Steroids

4 rings, eg cholesterol

Cholestorl is ____ which is

amphipatic, when hydrophobic and hydrophilic molecules are in structure tg

nonpolar molecules are

hydrophobic

polar molecules are

hydrophilic

phospholipids

make up the cell membrane, spontaneously form liposomes in water

polar head is ___ so its ___

hydrophilic, facing the outside

nonpolar tail is ____ so its____

hydrophobic, facing the inside