BIO101 Exam 2 Study Guide

Cell Theory

All organisms are composed of cells; cells come from preexisting cells; the cell is the basic unit of life.

Prokaryotic Cells

Cells that lack a membrane-bound nucleus.

Bacteria

One of the three domains; consists of prokaryotic cells.

Archaea

One of the three domains; consists of prokaryotic cells and can live in extreme habitats.

Eukarya

One of the three domains; consists of eukaryotic cells.

Cell Wall

Maintains the shape of a cell.

Nucleoid

The region where bacterial DNA is located in a prokaryotic cell.

Plasmid

Small, accessory rings of DNA that can be transferred.

Ribosomes

Structures that make proteins; their primary job is protein synthesis.

Cytoplasm

One of the four things all cells have in common.

Plasma Membrane

One of the four things all cells have in common; controls what enters and leaves the cell.

DNA

One of the four things all cells have in common; contains the cell's genetic information.

Fimbriae

Tiny hairs on the outside of prokaryotic cells that allow bacteria to attach to surfaces.

Eukaryotic Cells

Cells that have a membrane-bound nucleus.

Plant Cell Wall

Plant cells have a cell wall; animal cells do not.

Eukaryotic vs. Prokaryotic Cells

Eukaryotic cells are larger than prokaryotic cells and are compartmentalized.

Endosymbiotic Theory

The theory that mitochondria and chloroplasts may have originated when larger cells engulfed smaller prokaryotic cells.

Nucleus

The command center of the cell; contains the cell's DNA.

Nuclear Envelope

A double-layer membrane that separates the nucleus from the cytoplasm.

Chromatin

DNA wrapped around histone proteins.

Nucleoplasm

The semifluid material inside the nucleus that contains chromatin.

Nucleolus

A dark region of the nucleus composed of rRNA that produces ribosome subunits.

Nuclear Pores

Pores that permit exchange between the nucleoplasm and cytoplasm.

Rough Endoplasmic Reticulum (Rough ER)

The part of the endomembrane system where proteins are produced.

Smooth Endoplasmic Reticulum (Smooth ER)

Involved in lipid synthesis and detoxification; lipids can be carried in vesicles to the Golgi apparatus.

Golgi Apparatus

Modifies, stores, and packages proteins to go to various cells; compared to an Amazon warehouse in the study guide.

Lysosomes

Produced by the Golgi apparatus; function as cellular garbage disposal and contain powerful digestive materials.

Chloroplasts

Energy-related organelles in plant cells that are bounded by a double membrane.

Mitochondria

Energy-related organelles found in eukaryotic cells; known as the powerhouse of the cell.

Cristae

The inner membrane structures of mitochondria.

ATP

The energy produced by mitochondria; mitochondria produce ATP.

Central Vacuole

A gigantic vacuole in plant cells that helps create turgor pressure.

Turgor Pressure

Pressure created in plant cells by the central vacuole.

Exocytosis

The process of leaving the cell.

Endocytosis

The process of entering the cell.

Fluid Mosaic Model

The model describing the plasma membrane; includes proteins, a phospholipid bilayer, and cholesterol.

Phospholipid Bilayer

The main component of the fluid mosaic model of the plasma membrane.

Cholesterol

A component of the fluid mosaic model that regulates plasma membrane fluidity.

Selective Permeability

The characteristic of the plasma membrane that allows some substances to cross while restricting others.

Channel Protein

A membrane protein that allows specific molecules or ions to cross the membrane.

Cell Recognition Protein

A protein that helps cells identify foreign substances.

Receptor Protein

A protein that allows cells to communicate and signal.

Osmosis

The movement of water across a selectively permeable membrane from high to low concentration.

Isotonic

A condition where water moves in both directions with no net movement.

Hypotonic

A solution with a lower concentration; water moves into the cell.

Hypertonic

A solution with a higher concentration; water moves outside the cell.

Turgor Pressure from Hypotonic Solution

A hypotonic solution can cause turgor pressure in plants.

Lysis

A hypotonic solution may cause animal cells to lyse.

Crenation

Hypertonic conditions cause crenation in animal cells.

Plasmolysis

Hypertonic conditions cause plasmolysis in plant cells.

Diffusion

The movement of molecules down their concentration gradient from high to low concentration.

Passive Transport

Transport that does not require energy; diffusion is a form of passive transport.

Active Transport

The movement of molecules against their concentration gradient from low to high concentration.

ATP and Active Transport

Active transport requires energy in the form of ATP.

ADP and Phosphate

Subunits involved in ATP according to the study guide.

Substrate

The reactant in an enzyme-catalyzed reaction.

Product

The result of an enzyme-catalyzed reaction.

Active Site

The part of an enzyme that complexes with substrates.

Enzyme

A catalyst that speeds up a chemical reaction by lowering the activation energy.

Catalyst

A substance that speeds up a chemical reaction by lowering the activation energy.

Denaturation

The loss of an enzyme's shape, such as when an enzyme gets too hot.

Optimal pH

The particular pH at which an enzyme is optimized to function.

Temperature

Enzyme activity increases with temperature.

Noncompetitive Inhibition

An inhibitor binds to an allosteric site rather than the active site.

Allosteric Site

A site on an enzyme other than the active site; "allo" means "other."

Free Energy

The amount of energy available to perform work.

Degradation

An enzyme complexes with a single substrate molecule.

Synthesis

An enzyme complexes with two substrate molecules.