Cells and Organelles DAT Ch 2

DAT Ch 2

Cell Membrane

Selectively permeable barrier that controls what enters and exits the cell

Phospholipid Bilayer

Double layer of phospholipids with hydrophilic heads and hydrophobic tails.

Membrane Proteins

Embedded proteins that assist with transport, signaling, and structural support.

Fluid Mosaic Model

Describes the flexible membrane structure with proteins floating in a lipid bilayer.

Cholesterol

Lipid that stabilizes the membrane and affects its fluidity.

Simple Diffusion

Passive movement of molecules from high to low concentration without energy.

Facilitated Diffusion

Passive movement through a membrane via a protein channel or carrier.

Active Transport

Movement of substances against concentration gradient using ATP energy.

Endocytosis

Cell takes in substances by engulfing them in a membrane.

Exocytosis

Vesicles fuse with the cell membrane to release contents outside the cell.

Phagocytosis

"Cell eating" – endocytosis of large particles or other cells.

Pinocytosis

"Cell drinking" – endocytosis of fluids and dissolved substances.

Receptor-Mediated Endocytosis

Specific uptake of molecules using receptors on the membrane.

Organelle

Specialized structure within a cell that performs a distinct function.

Nucleus

Stores DNA and controls cell activities.

Nucleolus

Found inside the nucleus; makes ribosomes.

Ribosomes

Site of protein synthesis; can be free-floating or on the rough ER.

Rough Endoplasmic Reticulum (Rough ER)

studded with ribosomes; synthesizes and processes proteins.

Smooth Endoplasmic Reticulum (Smooth ER)

Makes lipids, detoxifies chemicals, and stores calcium.

Golgi Apparatus

Modifies, packages, and ships proteins and lipids

Lysosome

Contains enzymes for breaking down waste and cell debris.

Peroxisome

Breaks down fatty acids and detoxifies harmful compounds.

Mitochondrion

Produces ATP via cellular respiration; powerhouse of the cell

Chloroplast

Site of photosynthesis in plant cells.

Cytoskeleton

Internal framework made of protein filaments that supports cell shape and movement.

Microfilaments

Thin protein filaments involved in movement and cell division.

Intermediate Filaments

Provide structural stability to cells.

Microtubules

Hollow tubes that assist in cell shape, transport, and division.

Extracellular Matrix (ECM)

Network outside animal cells that provides structural and biochemical support. Including Proteoglycans, Collagen, Integrin, Fibronectin, and Laminin

Cell-Matrix Junctions

Structures that connect cells to the ECM, like hemidesmosomes.

Cell-Cell Junctions

Structures like tight junctions, desmosomes, and gap junctions that connect cells.

Osmosis

Diffusion of water through a semipermeable membrane toward higher solute concentration

Hypertonic Solution

Has more solutes than the cell; causes water to leave the cell

Hypotonic Solution

Has fewer solutes than the cell; causes water to enter the cell

Turgid

FFirm and swollen plant cell in a hypotonic environment.

Plasmolysis

Plant cell shrinking due to water loss in a hypertonic environment.

Epithelial Tissue

Covers body surfaces and lines cavities

Connective Tissue

Supports, protects, and binds other tissues and organs.

Muscle Tissue

Responsible for body movement; includes skeletal, cardiac, and smooth types.

Nervous Tissue

Sends electrical signals throughout the body; includes neurons and glial cells.