Biology 2 Cells and Organisms

Cell theory

idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells

Life processes of living things

Maintaining a stable internal environment
Controlled exchange of materials
Response to stimuli
Obtaining energy and chemical elements
Transport of materials
Removal of wastes
Cell division
Growth, development and repair
Independent movement
Reproduction

Unicellular organisms

Living things made up of only one cell

Multicellular organisms

Living organisms made up of two or more cells

Prokaryote

A small, relatively unspecialised, are mostly unicellular and are defined by the fact they do not have a nucleus

Eukaryote

A cell that contains a nucleus and membrane bound organelles

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Flagellum

A long, hairlike structure that grows out of a cell and enables the cell to move.

Ribosomes

site of protein synthesis

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

nucleoid region

The region in a prokaryotic cell consisting of a concentrated mass of DNA.

plasma membrane

A selectively

cell wall

A rigid structure that surrounds the cell membrane and provides support to the cell

Capsule (prokaryotes)

jelly like outer coating

Plasmid

A small ring of DNA that carries accessory genes separate from those of the bacterial chromosome

Pili

Appendages that allow bacteria to attach to each other and to transfer DNA

Membrane bound organelles

organelles in eukaryotic cells that are surrounded by a lipid bilayer membrane

Endosymbiosis

A theorized process in which early eukaryotic cells were formed from simpler prokaryotes.

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Mitochondria

An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur.

Nucleus

A part of the cell containing DNA

Rough Endoplasmic Reticulum (RER)

processes and transports proteins made at attached ribosomes

Smooth Endoplasmic Reticulum (SER)

Fatty acid and steroid synthesis; detoxifies toxic substances

Golgi apparatus

stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum

Ribosome

site of protein synthesis

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

Cell wall

A rigid structure that surrounds the cell membrane and provides support to the cell

Plasma membrane

A selectively

Cytosol

Fluid portion of cytoplasm

Phospholipid

A molecule that makes up the bilayer of membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

hydrophilic

water loving

hydrophobic

water hating

integral protein

A transmembrane protein with hydrophobic regions that extend into and often completely span the hydrophobic interior of the membrane and with hydrophilic regions in contact with the aqueous solution on one or both sides of the membrane (or lining the channel in the case of a channel protein).

peripheral protein

A protein loosely bound to the surface of a membrane or to part of an integral protein and not embedded in the lipid bilayer.

glycoprotein

A protein with one or more carbohydrates covalently attached to it.

Glycolipids

carbohydrates covalently bonded to lipids

polar

Molecule with partial charges. Mixes with water.

non

polar

simple diffusion

movement of a solute from an area of high concentration to an area of low concentration

faciliated diffusion

process of diffusion in which molecules pass across the membrane through cell membrane channels, no energy required

osmosis

Diffusion of water through a selectively permeable membrane to an area of high solute concentration

tonicity

The ability of a solution surrounding a cell to cause that cell to gain or lose water.

hypotonic

Having a lower concentration of solute than another solution

hypertonic

Having a higher concentration of solute than another solution.

lysed cell

Cell that has burst in a high solute, low solvent environment

plasmolysed

plant cell where the contents have shrunk due to loss of water by osmosis and the plasma membrane has separated from the cell wall

Flaccid plant cell

A plant cell which is limp due to lack of water

turgid

swollen

passive transport

Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient

active transport

Energy

bulk transport

The process by which large particles and macromolecules are transported through plasma membranes. Includes exocytosis and endocytosis

endocytosis

A process in which a cell engulfs extracellular material through an inward folding of its plasma membrane.

exocytosis

a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.

surface area to volume ratio

a comparison of the amount of surface area per unit of volume. In Biology, SA:V influences temperature regulation, and a high SA:V leads to more effective transport into and out of cells.

enzymes

Proteins that speed up (catalyse) chemical reactions

catalyst

substance that speeds up the rate of a chemical reaction

activation energy

the minimum amount of energy required to start a chemical reaction

reactant

A chemical substance that is present at the start of a chemical reaction

product

A substance produced in a chemical reaction

substrate

a substance that reacts to the active site of an enzyme

induced fit model of enzyme action

enzyme changes shape to "grasp" the substrate

competitive inhibitor

competes with substrate for active site

non

competitive inhibitor

denature

A change in the shape of a protein (such as an enzyme) that can be caused by changes in temperature or pH (among other things).

gene

A segment of DNA on a chromosome that codes for a specific trait

nucleic acid

DNA and RNA

nucleotide

A building block of DNA, consisting of a five

complementary base pairing

In DNA, T pairs with A; G pairs with C;
RNA, U pairs with A and G pairs with C

chromosome

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

ribonucleic acid (RNA)

A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single

DNA polymerase

Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule

gene expression

the process of reading the information stored within a gene to create a protein

protein synthesis

The creation of a protein from a DNA template.

transcription

synthesis of an RNA molecule from a DNA template

translation

Process by which mRNA is decoded and a protein is produced

monomer

A simple compound whose molecules can join together to form polymers

polymer

A long molecule consisting of many similar or identical monomers linked together.

RNA polymerase

enzyme that links together the growing chain of RNA nucleotides during transcription using a DNA strand as a template

peptide

short chain of amino acids

polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds.

codon

three

anti

codon

tRNA (transfer RNA)

type of RNA molecule that transfers amino acids to ribosomes during protein synthesis

mRNA (messenger RNA)

a single

rRNA (ribosomal RNA)

type of RNA that makes up the major part of ribosomes

peptide bond

covalent bond formed between amino acids

interphase

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases

mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

chromatid

one of two identical "sister" parts of a duplicated chromosome

daughter cells

new cells produced by cell division

prophase

DNA condenses to form distinct chromosomes
Mitotic spindle forms
Nuclear membrane breaks down

metaphase

Each sister chromatid is attached to a spindle fibre
Chromosomes align along the metaphase plate

anaphase

Sister chromatids (now called chromosomes) are pulled to opposite poles
Cell is elongated

telophase

Chromosomes decondense
Nuclear envelope reforms

cytokinesis

Division of the cytoplasm during cell division

binary fission

A form of asexual reproduction in which one cell divides to form two identical cells.

primary protein structure

sequence of amino acids

secondary protein structure

coiling or folding of a polypeptide due to H

tertiary protein structure

3D folding pattern of a single polypeptide chain due to side chain interactions

quaternary protein structure

association between two or more polypeptide chains creating a 3D shape