Chapter 10.2

Cell Theory

All living organisms are made up of one or more cells; the cell is the basic unit of structure and function; all cells arise from pre-existing cells.

Plasma membrane

Controls what enters and exits the cell.

Cytoplasm

Jelly-like substance that holds cellular contents.

Ribosomes

Sites of protein synthesis.

Genetic material

Carries instructions for cellular activities, can be DNA or RNA.

Eukaryotic Internal Membrane System

Includes nuclear envelope, rough/smooth ER, Golgi apparatus, lysosomes, endosomes, transport vesicles, plasma membrane, peroxisomes, and vacuoles.

Mitochondria

Organelles that produce ATP through cellular respiration and have their own membranes.

Chloroplasts

Organelles in plant cells that conduct photosynthesis.

Phospholipid bilayer

Double layer of phospholipids that forms the cell membrane; has hydrophilic heads and hydrophobic tails.

Hydrophilic heads

The part of phospholipids that face outward toward water.

Hydrophobic tails

The part of phospholipids that face inward, away from water.

Proteins (in cell membrane)

Molecules that assist in transport, signal reception, and cell recognition.

Carbohydrates (in cell membrane)

Typically attached to proteins/lipids on the extracellular surface for cell recognition.

Cholesterol

Molecule in the cell membrane that maintains fluidity and stability.

Nucleus

Stores genetic material; site of RNA synthesis.

Rough ER

Studded with ribosomes; produces proteins for secretion or membrane insertion.

Smooth ER

Lacks ribosomes; synthesizes lipids and detoxifies chemicals.

Golgi Apparatus

Modifies, sorts, and packages proteins and lipids for distribution.

Lysosomes

Digestive compartments that break down macromolecules and old organelles.

Microfilaments

Components of the cytoskeleton that provide structure and assist with cell movement.

Intermediate Filaments

Provide strength and mechanical stability to the cell.

Microtubules

Cytoskeletal components involved in transport, mitosis, and structural support.

Saturated fats

Fats with no double bonds, straight chains, and solid at room temperature.

Unsaturated fats

Fats with one or more double bonds, kinked chains, and liquid at room temperature.

Active Transport

The movement of substances across a membrane against the concentration gradient, requiring energy.

Primary Active Transport

Uses ATP directly to move ions against their concentration gradient.

Secondary Active Transport

Utilizes the electrochemical gradient created by primary transport to move other substances.

Secretory Pathway of a Protein

Process including synthesis in rough ER, modification in Golgi, packaging in vesicles, and release by exocytosis.

Dynamic Instability of Microtubules

Rapid growth and shrinkage of microtubules allowing cellular reorganization.

Liposomes

Vesicles that mimic cell membranes, used for drug delivery into cells.

Transport Proteins

Proteins that assist large, polar or charged molecules in crossing the cell membrane.

Simple diffusion

Movement of small or nonpolar molecules across the membrane directly.

Facilitated diffusion

Process that uses proteins to help larger or polar molecules cross the membrane.

Osmosis

Diffusion of water across a semipermeable membrane.

Concentration gradient

The difference in concentration of a substance across a space.

Endoplasmic Reticulum (ER)

Network of membranes involved in protein and lipid synthesis.

Golgi Apparatus

Organelle responsible for modifying, sorting, and packaging proteins and lipids.

Vesicles

Small membrane-bound sacs that transport materials within cells.

Vacuoles

Storage organelles found in cells, often larger in plant cells.

Peroxisomes

Organelles involved in the breakdown of fatty acids and the detoxification of harmful substances.

Cell Membrane

Barrier that separates the interior of the cell from the external environment.

Cellular Respiration

Process by which cells generate ATP from glucose and oxygen.

Photosynthesis

Process by which plants convert light energy into chemical energy.

Chemical gradients

Differences in the concentration of substances across a cellular membrane.

Endosomes

Membrane-bound compartments that sort endocytosed material.

Protein synthesis

The process by which cells produce proteins.

Cell recognition

The ability of cells to identify and interact with other cells.

Cellular activities

Processes and functions carried out by cells to maintain life.

Biological membranes

Membranes that separate and protect cellular environments.

Antiparallel structure

Arrangement of phospholipids in the bilayer where one layer faces one direction and the other faces the opposite.

Electrochemical gradient

A gradient produced by the differences in ion concentration and electrical charge across a membrane.

Phospholipid

Molecule that forms the basis of cellular membranes, with hydrophilic heads and hydrophobic tails.

Membrane fluidity

The viscosity of the lipid bilayer of a cell membrane, affecting the movement of proteins and lipids.

Signal reception

The process of cells detecting and responding to chemical signals.

Selective permeability

The property of cell membranes that allows certain substances to pass while blocking others.

Chemiosmosis

Movement of ions across a selectively permeable membrane down their electrochemical gradient.

Cell signaling

The communication process that governs the basic activities of cells and coordinates cellular activities.

Nuclear envelope

Double membrane that surrounds the nucleus in eukaryotic cells.

Similarity between mitochondria and chloroplasts

Both have their own DNA and double membranes.