Unit 4: Chemistry and Structure of Life

Biosphere

Global sum of all ecosystems on Earth.

Ecosystem

Community of living organisms and their environment.

Community

Group of interacting populations in a specific area.

Population

Group of individuals of the same species.

Organism

Individual living entity capable of growth.

Organ Systems

Groups of organs working together for a function.

Tissue

Group of similar cells performing a specific function.

Cell

Basic unit of life, smallest structural unit.

Organelle

Specialized subunit within a cell.

Molecule

Stable association of two or more atoms.

Covalent Bond

Strong bond formed by shared electrons.

Electronegativity

Attraction of an atomic nucleus for electrons.

Hydrogen Bonds

Attraction between hydrogen and electronegative atoms.

Hydrophilic

Substances that dissolve easily in water.

Hydrophobic

Substances that do not dissolve in water.

pH

Measure of acidity or alkalinity in a solution.

Acids

Release H+ ions when dissolved in water.

Bases

Release OH- ions or accept H+ ions.

Lipids

Nonpolar molecules including fats and oils.

Triglycerides

Fats and oils composed of glycerol and fatty acids.

Phospholipids

Molecules forming cell membranes, amphipathic nature.

Nucleic Acids

Polymers for genetic information storage and transmission.

Nucleotides

Monomers of nucleic acids, composed of sugar, base, phosphate.

Glycerol

has three -OH groups

Fatty Acid

nonpolar hydrocarbon with a polar carboxyl group

Ester bond

when carboxyls interact with hydroxyls of glycerol (condensation reactions)

Saturated fats

animal fats: tight, straight tails, solid at room temperature

unsaturated fats

plant oils: kinks prevent packing, liquid at room temperature

amphipathic

molecule with opposing chemical properties

monosaccarides

simple sugars

disaccharides

two simple sugars linked by covalent bonds

oligosaccharides

3-20 monosaccharides

polysaccharides

hundreds or thousands of monosaccharides

hexoses

6 carbon sugars

pentoses

5 carbon sugars

Carbohydrates are... (soluble or insoluble)

soluble

cellulose

stable structure found in plants

starch

storage of gluten in plants

glycogen

storage of gluten in animals

nucleic acids

polymers specialized for the storage, transmission, and use of genetic information

nucleotides

monomers of nucleic acids

What is in a nucleotide

Nitrogenous base + sugar (ribose or deoxyribose) and phosphate group

Pyrimidines (one ring)

C, T, U

purines (two rings)

A, G

peptide bonds

link amino acids through condensation

primary structure

string of amino acids

secondary structure

interactions between amino and carboxyl groups to form helices and sheets

tertiary structure

interactions between R groups

What composes an amino acid?

connected to a central carbon, there is an amino group, carboxyl group, hydrogen atom, and a variable R group (side chain)

integral proteins

embedded in lipid structure

peripheral proteins

not embedded in the lipid bilayer, interact with phospholipid heads

anchored proteins

covalently attached to lipids

diffusion

movement from an area of higher concentration to an area of lower concentration

osmosis

diffusion of water

hypertonic

higher solute concentration

isotonic

equal concentrations

hypotonic

lower solute concentration

passive transport

no outside E required (diffusion)

active transport

E required (usually ATP)

simple fusion

small, nonpolar, hydrophobic molecules can pass through membrane

channel proteins

transmembrane proteins that form a channel

carrier proteins

transmembrane proteins that bind to substances and speed their diffusion through bilayer

ion channels and gated/open when...

protein is stimulated to change shape, or a charge difference

exocytosis

Process by which a cell releases large amounts of material

endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

prokaryotic cells (bacteria and archea)

do not have a nucleus or other membrane-bound organelles

eukaryotic cells (plants, animals)

membrane-bound organelles, including a nucleus

cytoplasm

material within the cell (except nucleus)

endomembrane system

surrounds nucleus with pores tha tcontrol movement. runs into endoplasmic reticulum

rough endoplasmic reticulum (RER)

Ribosomes attached, proteins are modified and folded

Smooth Endoplasmic Reticulum (SER)

steroid synthesis

golgi apparatus

receives from RER, more modifications, sends proteins off

ribosomes

site of protein synthesis (similar to P. and E. cells)

mitochondria

double membrane, energy transformed into ATP through cellular respiration

chloroplasts

site of photosynthesis, double membrane

Exergonic

reactions release free energy

Endergonic

reactions absorb free energy

Anabolic reactions

Simple molecules make complex molecules

Catabolic reactions

complex molecules break down into simpler ones, releasing energy.

active sites

substrates bind to specific spots on enzymes where catalysis occurs.

allosteric regulation

molecules interact with enzymes and change its shape

Enzyme substrate complex

held together by hydrogen bonds, electrical attraction, temporary covalent bonds, van der Waals

non covalent binding

activator or inhibitor associate with regulatory part of protein (overall shape changes)

covalent modification

molecule covalently bonds to enzyme (changes shape of active site)

Active site inhibition

bind to active site to prevent substate from entering active site