AP Biology Ultimate Vocab

atomic number

number of protons an element contains (determines identity of the element)

atomic mass

number of protons AND neutrons an element contains

isotopes

elements with the same # of protons but different # of neutrons

chemical bonds

interactions result in atoms staying close together (+/-)

covalent bonds

 sharing a pair of valence electrons by 2 atoms

molecule

2 or more atoms held together by covalent bonds

electronegativity

an atom’s attraction for the electrons in a covalent bond

nonpolar covalent bond

atoms share electrons equally

polar covalent bond

1 atom is more electronegative and atoms do not share electrons equally

ionic bonds

result from the attraction of opposite-charged ions (+/-)

ionic compounds (salts)

compounds formed by ionic bonds

hydrogen bonds

forms when a hydrogen atom covalently bonded to one electronegative atom (partial +) is attracted to another strongly electronegative atom in a different molecule

proteins

• Proteins play a role in the structure of cells & can speed up the rate of chemical reactions

• Proteins are made up of subunits called amino acids

  • A protein is like a necklace & an amino acid like a bead

nucleic acids

• Information molecules and the molecules of heredity

• Made up of subunits called nucleotides

carbohydrates

• AKA sugars

• Store energy & make up the external layer of some types of cells

• Made up of simple sugars called monosaccharides

lipids

Hydrophobic molecules that make up the cell membrane, store energy, and act as chemical messengers

hydrophilic substance

one that has an affinity for water (loves water); ionic, polar, charged

hydrophobic substance

one that does not have an affinity for water (fears water); nonpolar, not charged, neutral

capillary action

cohesion + adhesion (Help the transport of water against gravity in plants)

cohesion

water molecules attracted to each other

adhesion

the tendency of water molecules to be attracted, or ''stick'', to other substances

surface tension

measure of how hard it is to break the surface of a liquid; related to cohesion; water has it higher than most other liquids

evaporative cooling

as a liquid evaporates, its remaining surface cools

evaporation

change of a substance from liquid to gas

pH

measure of the acidity of a solution

dehydration synthesis reactions

remove water and join smaller molecules to form larger molecules to form larger molecules linked by covalent bonds (WATER IS PRODUCT)

hydrolysis reactions

add a water molecule across a covalent bond and break large molecules into smaller ones (WATER IS REACTANT)

monomer

single molecule/building block of an organic molecule/macromolecule

polymer

a large molecule made up of 2 or more monomers bonded together

monosaccharides

monomers of carbs that join together to form monomers

glucose

the main biological carb monomer

maltose

glucose + glucose

glycosidic bond

join monosaccharides together

polysaccharides

many sugars

signaling

 steroid hormones

membranes

phospholipids that have different chemical properties on either end (amphipathic)

unsaturated

1 or more C-C double bonds

saturated

No C-C double bonds

Van der Waals

weak, noncovalent interaction that tightly packs fatty acids in lipids

amino acids

consists of a carbon connected by covalent bonds to an amino group, a carboxyl group, a hydrogen atom, and a side chain/R group

enzyme

catalyze (speed up) chemical reactions

peptide bonds

connect amino acids to form proteins

secondary structure 2°

results from hydrogen bonds between nearby amino acids  (Alpha helix and Beta sheet)

polypeptide

string of amino acids

alpha helix

the backbone of the protein is twisted (spiral coil)

beta pleated sheet

parallel primary chains (folded paper fan); runs in same/opposite directions

quaternary structure 4°

forms when 2 or more polypeptide subunits form a protein

denaturation

3D shape of a protein can be destroyed in adverse environment (temperature, pH, salinity)

nucleotides

composed of a nitrogen-containing base, a 5-carbon sugar, & phosphate group

pentose

5-carbon sugar

purines

A & G (bases with a double ring structure)

pyrimidines

C & T (bases with a single ring structure)

phosphodiester bond

dehydration synthesis of polynucleotide chain

nucleotide triphosphates

react with a strand of DNA to make the polymer one nucleotide longer

cell theory

• The basic unit of life

• Consists of cells → unicellular or multicellular

• Cells come from preexisting cells

cell membrane

he boundary that separates the cell from its environment (maintains homeostasis in the cell)

metabolism

the set of chemical reactions in cells that build and break down macromolecules and harness energy

prokaryotes

• Includes bacteria and archaea

• Typically much smaller than eukaryotic cells

• Lack nucleus and extensive internal membrane-enclosed compartments (nucleoid)

• Contains only free ribosomes

• One large circle

• Often contains smaller circular molecules of DNA known as plasmids

Can be transferred between cells through threadlike structures known as pili

eukaryotes

• Evolved much later than prokaryotes

• Includes animals, plants, fungi, and protists

• Have a nucleus and other internal compartments called organelles

• Contains ribosomes (both membrane-bound and free)

• Single-celled eukaryotes move by motile cilia

endosymbiont theory

Mitochondria and chloroplasts display similarities with primitive bacteria

nucleus

enclosed by double membrane called nuclear envelope; houses genetic material

nuclear pores

protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm

dna (chromatin/chromosomes)

genetic material

nucleolus

making the ribosomes inside the nucleus

ribosomes (free or ER bound)

protein synthesized; read the RNA

rough er

proteins synthesized here

smooth er

lipids synthesized here

golgi apparatus

packages the molecules from the ER to be sent out

vesicles

small sac formed by a membrane and filled with liquid; moves substances into or out of the cell

lysosomes

use enzymes inside to break down waste material; only in animal cell

vacuoles

 holds water; breaks down waste in a plant (in plant cells only)

mitochondria

transfer energy from chemical compounds for use by nearly all cells

chloroplasts

harness the energy of sunlight to make ATP and build sugars in plant and algal clls (photosynthesis occurs here) (in plant cells only)

peroxisome

breaking down, mostly lipids, w/ oxidative reactions and hydrogen peroxide is the byproduct

cytoskeleton

consists of microfilament and microtubules that help maintain cel shape/structure

centrioles

an organelle that helps cells divide, or make copies of themselves (looks like pasta) (animal only)

cell wall

made of cellulose; helps to maintain cell structure and turgor pressure (plant only)

cilia & flagella

help with movement of cell

endomembrane system

interconnected system of membranes that defines spaces in a cell, synthesizes important molecules, and traffics/sorts these molecules into and out of the cell

surface area

measure of total surface of 3 dimensional object

volume

 the measure of total space occupied by 3 dimensional object

diffusion

the net movement of molecules from regions of higher concentration to regions of lower concentration due to random motion

bulk flow

process in which fluids move by pressure differences at rates much greater than is possible by diffusion

extracellular

outside

intracellular

inside

regulatory barrier

passive & active transport

selective permeability

the membrane allows only particular molecules to permeate (pass through) the membrane

fluid “mosaic”

cell membrane is made up of moveable pieces made of molecules (lateral, not transverse)

phospholipid bilayer

double layer of phospholipids forms the structure of cell membranes

amphipathic structure

one part likes water, another part doesn’t); depends on temperature

glycolipid and glycoprotein

receptors on the cell surface for communication

intracellular junctions

getting communication in through cell communication; a part of the membrane proteins

aquaporin

ONLY lets water through

transmembrane proteins

proteins that span the membrane

integral

protein is going all the way through the membrane or there are 2 proteins together

peripheral

protein is lying on the side of the membrane → one end or the other → DOES NOT go through all the way

gradient

difference in concentrations between 2 points

passive transport

molecules move from high to low concentration (down the gradient)

simple diffusion

• Molecules move right through the membrane

• Small, nonpolar, neutral, hydrophobic

facilitated diffusion

• TOP ~ molecules move through protein channels (hydrophilic tunnels)

• BOTTOM ~ molecules move through the protein carriers (change shape)