Cell Biology Definitions

Every definition from the class

Nucleus

Membrane bound control center, holds DNA, produces ribosomes

Nuclear Envelope

same as lamina but the outer layer

Nuclear Pores

Protein channels that allow movement in and out

Nucleolus

Stores RNA

Nuclear Lamina

Protein meshwork that provides structure and regulates many nuclear processes (inner part)

Ribosomes

Make proteins, either attached or free floating

Rough ER

Protein producing and transporting

Smooth ER

Produces some types of lipids, detoxification

Golgi Apparatus

Packaging center for proteins

Mitochondria

Produces ATP

Lysosome

Digests biomolecules

Vacuole

storage

Chloroplast

Makes glucose through photosynthesis

Centrioles

Pulls chromosomes apart during cellular division

Plasma Membrane

Barrier that controls what comes and goes

Chromatin

DNA and proteins

Chromosome

Tightly packed chromatin

Vesicles

Transporting proteins, mostly to the golgi apparatus

Peroxisome

Breaks down fatty acids/amino acids

Free Ribosome

Produces proteins

Bound Ribosome

Produces proteins for membranes, other cells, and organelles

Cytoskeleton

protein framework that gives support, shape, and mobility

Microtubules

Hollow tubes that keep the cell shape and create cilia/flagella, helps the cells move, made of tubulin

Flagella

tails that rotate to move the cell

Cilia

Tiny hair-like structures that move the cell

Microfilaments

Two intertwined strands of actin that help the maintenance of cell shape (tension bearing elements)

Intermediate Filaments

Fibrous proteins that help maintain the cell shape, anchorage of the nucleus and other organelles

Cell Wall

Thicker than the plasma membrane, less flexible

Prokaryotes

No membrane-bound organelles, unicellular, have a cell wall, DNA is free floating, one circular chromosome E

Eukaryotes

Plants, animals, fungi, membrane-bound organelles, single and multi-celled, multiple linear chromosomes

Carbohydrates

Made up of monosaccharides, provides the body with energy

Lipids

Made up of glycerol and fatty acids, make up the cell membrane, source of long-term energy, can act as hormones, insulation

Proteins

Made up of amino acids, act as enzymes, antibodies, and some critical hormones

Nucleic Acid

Made up of nucleotides, make up DNA

Covalent Bonds

Strong, shared pair of electrons between atoms

Nonpolar

atoms share electrons equally

Polar

Some atoms pull electrons towards themselves

Ionic Bonds

One atom steals an electron from the other

Ions

Charged atoms

Hydrogen Bond

A weak bond between two molecules

DNA

Double-stranded helix, center is made up of nitrogenous bases, makes up genes

RNA

Single-stranded, codes for proteins, uracil instead of thymine

Promoter

Where transcription starts, where RNA polymerase begins

Terminator

Signals the end of transcription

RNA Polymerase

Synthesizes RNA while following DNA

Transcription Factors

Proteins that regulate the process of transcription

Simple Diffusion

A passive process where molecules move from high to low concentration toward equilibrium

Facilitated Diffusion

Proteins act as channels or carriers

Osmosis

Water moves through the membrane, the solute can’t

Tonicity

Measure of osmotic pressure

Active Transport

Uses ATP and requires a protein channel

Tight Junctions

Keeps things from passing through the cell barrier

Adhesive Junctions

Holds cells together

Gap Junctions

Allows cells to share molecules

Reception

Receptor and ligand bind

Transduction

Signal transduction

Response

Cellular responses

Phototroph

Use light as their source of energy

Chemotroph

Obtains energy through the oxidation of electron donors in their environment

Heterotroph

Eats other plants/animals for energy

Autotroph

Can produce its own food

Catabolism

A larger molecule being broken down into smaller molecules and energy

Anabolism

Small molecules and energy being made into larger molecules

Endergonic Reaction

A reaction that requires energy to be absorbed in order to take place

Exergonic Reaction

A reaction that releases energy

Cofactor

A helper molecule for enzymes

Competitive Inhibitor

substrate binding is blocked, can be overcome with more substrate

Noncompetitive Inhibitor

Substrate can bind but reaction is blocked, cannot be overcome by changing substrate concentration

Allosteric Regulator

Regulatory molecule binding to the allosteric site, can activate or inhibit enzymes

Glycolysis

Turns glucose into pyruvate

Pyruvate Oxidation

Pyruvate oxidized into Acetyl-CoA

Citric Acid Cycle

CoA is turned into CO2 and reduced electron carriers

Oxidative Phosphorylation

ETC and chemiosmosis produces ATP

Light-dependent Reactions

Takes place in the thylakoid membrane

Light-independent Reactions

Takes place in the stroma