AP Bio Chapter 6

cytosol

The fluid portion of the cytoplasm that surrounds organelles in a cell.

prokaryotic

The cell type with the domain of bacteria and archaea

nucleoid

The region within a prokaryotic cell where the circular DNA is located.

eukaryotic

Describing organisms whose cells contain a distinct nucleus and membrane

cytoplasm

The entire contents of a cell bounded by the plasma membrane, excluding the nucleus.

plasma membrane

The phospholipid bilayer that acts as a selective barrier surrounding the cell.

surface area

The total area covering the outer boundary of a three dimensional shape or closed container

volume

The total amount of 3 dimensional space taken up by a closed container

surface area to volume ratio

The relationship showing how much exterior area is available relative to the interior size of an object or cell.

nucleus

A membrane-bound organelle found in eukaryotic cells that houses DNA

nuclear envelope

The double membrane structure that encloses the nucleus and regulates molecular transport via pores.

nucleolus

A dense region inside the nucleus where ribosomal RNA is synthesized and ribosome subunits are assembled.

ribosome

A cellular structure made of RNA and protein that synthesizes proteins.

free ribosome

A ribosome floating in the cytosol that produces proteins intended to function inside the cytoplasm.

bound ribosome

A ribosome attached to the endoplasmic reticulum or nuclear envelope that synthesizes proteins for membranes or export.

endomembrane system

A network of interior membranes in eukaryotic cells that work together to synthesize, modify, and transport proteins and lipids.

vesicles

A small, membrane-bound sac inside a cell that stores and transports materials

endoplasmic reticulum

An extensive network of membranous tubules and sacs involved in protein and lipid synthesis.

smooth ER

The portion of the endoplasmic reticulum that lacks ribosomes and synthesizes lipids, metabolizes carbohydrates, and detoxifies chemicals.

rough ER

The portion of the endoplasmic reticulum studded with ribosomes that processes and folds proteins.

golgi apparatus

An organelle that modifies, sorts, and packages proteins and lipids for delivery or secretion.

lysosome

a tiny, membrane-bound cell organelle that acts as the recycling center and garbage disposal of animal and other eukaryotic cells

vacuoles

A membrane-bound organelle inside a cell that acts as a storage compartment for water, nutrients, and waste products

central vacuole

A large organelle in plant cells that stores water, nutrients, and waste while maintaining turgor pressure.

tonoplast

The membrane surrounding the central vacuole in a plant cell.

mitochondrion

The organelle responsible for cellular respiration and generating ATP.

chloroplast

The plant and algal organelle that conducts photosynthesis to convert light energy into chemical energy.

peroxisome

A specialized metabolic organelle that neutralizes toxins and breaks down fatty acids, producing hydrogen peroxide as a byproduct.

cytoskeleton

A network of protein fibers that provides structural support, maintains cell shape, and facilitates movement.

microtubules

Hollow tubes made of tubulin proteins that shape the cell, support organelle movement, and separate chromosomes during cell division.

centrosome

A structure near the nucleus that acts as the primary microtubule

centrioles

Paired cylindrical structures within the centrosome that help organize microtubule assembly.

flagella

Long, whip

cilia

Short, hair

cell wall

A rigid outer layer surrounding the plasma membrane in plant, fungal, and bacterial cells that provides support and protection.

cellulose

A tough polysaccharide carbohydrate that forms the structural foundation of plant cell walls.

extracellular matrix

A meshwork of proteins and carbohydrates secreted outside animal cells that provides support and facilitates cell signaling.

collagen

A structural glycoprotein in the extracellular matrix of animal cells that offers high tensile strength.

integrins

Transmembrane proteins that anchor the cell cytoskeleton to the extracellular matrix.

plasmodesmata

Channels through plant cell walls that allow direct transport and communication between adjacent cells.

tight junctions

Intercellular connections that form a continuous seal (watertight)

desmosomes

Anchoring junctions that fasten animal cells together into strong structural sheets.

gap junctions

Channels that physically connect the cytoplasm of adjacent animal cells to allow communication and chemical transport.