Unit 2 Review

Prokaryotic cells

Prokaryotic cells

Simpler in structure cells found in bacterial organisms.

Eukaryotic cells

More complex cells that contain membrane-bound organelles and are found in animals, plants, fungi, and protists.

Ribosomes

Structures that function in protein synthesis and are made of proteins and ribosomal RNA (rRNA).

Nucleoid region

The area in prokaryotic cells where circular genetic material is stored.

Plasmids

Small circular pieces of genetic material often found in some forms of bacteria.

Endoplasmic Reticulum (ER)

An organelle formed of smooth and rough sections, involved in lipid synthesis and protein synthesis.

Golgi complex

A stack of flattened membrane sacs that modify and package proteins for transport.

Lysosomes

Membrane-bound sacs containing hydrolytic enzymes used for digestion and breaking down worn-out cellular parts.

Vacuoles

Membrane-bound sacs for storage of food, water, or waste in cells.

Mitochondria

Organelles that produce energy (ATP) for the cell through cellular respiration.

Chloroplasts

Organelles found in plants and algae that carry out photosynthesis.

Cytoskeleton

Fiber structures that help give cells their shape and move items within the cell.

Fluid Mosaic Model

Describes the plasma membrane structure; it is selectively permeable with various proteins and lipids.

Passive Transport

The movement of molecules in/out of a cell without energy, moving from high to low concentration.

Active Transport

The movement of molecules from low to high concentration, requiring energy input, against the concentration gradient.

Aquaporins

Special proteins that facilitate the movement of water in/out of cells.

Hypotonic solution

A solution with a lower concentration of solute outside the cell, causing the cell to swell.

Hypertonic solution

A solution with a higher concentration of solute outside the cell, causing the cell to shrink.

Isotonic solution

A solution with equal concentrations of solute inside and outside the cell, maintaining cell pressure.

Water potential

The potential energy of water in a solution and its ability to do work, influenced by solute concentration.

Endocytosis

The process by which cells take in water and macromolecules using vesicles formed from the plasma membrane.

Exocytosis

The process where vesicles merge with the cell membrane to expel molecules from the cell.

Compartmentalization

The formation of membrane-bound organelles that increases cellular efficiency by separating metabolic processes.

Surface area to volume ratio (SA:V)

A ratio that affects cell efficiency; larger cells have a lower SA:V ratio.

Cytosol

The fluid component of the cytoplasm where organelles are suspended.

Nucleolus

A non-membrane-bound region in the nucleus where ribosomes are assembled.

Endosymbiosis hypothesis

Theory that mitochondria and chloroplasts originated from free-living prokaryotes absorbed by larger prokaryotes.

Hydrolytic enzymes

Enzymes that break down macromolecules into their simplest units.