Unit 4: Cells And Material Transport Flashcards
Active transport
Movement of ions or molecules across a membrane , often against a concentration gradient; requires energy input
Anton Van Leeuwenhoek
First person to see living cells
Carrier protein
Carrie’s the ion or molecule across the cell membrane by changing shape after the building of the ion or molecule; involved in both active and passive transport
Cell membrane (plasma membrane)
The boundary that surrounds a cell and controls which substances can enter or leave the cell
Cellulose
An insoluble polymer that is the main substance in plant wall cells
Central vacuole
A large sac in the cytoplasm; stores water, nutrients, waste products, and other materials in plant cells
Centrioles
Organelles involved in cell division; they organize the chromosomes before cell division so each daughter cell has the correct number of chromosomes after the cell divides
Channel proteins (protein channels)
Type of transport that acts like a pore in the cell membrane; allows water or small ions to pass through quickly
Chloroplast
An organelle in a plant cell that turns energy from the sun into chemical energy for the plant to use
Concentration gradient
Unequal concentration form one region to another
Cytoskeleton
A network of protein fibers found in eukaryotic cells
Diffusion
When particles spread out, moving from a region of high to low concentration
Endocytosis
A process in which cells take in materials by wrapping a section of plasma membrane around the materials and bring them into the cell
Exocytosis
A pro elk in which cells expel materials within a vesicle by fusing the vesicle to the plasma membrane
Facilitated diffusion
When chemicals cannot cross the membrane directly, they diffuse across the membrane through transport proteins; the proteins help the process of diffusion
Fluid mosaic model
Describes the structure of the cell membrane; that proteins and lipids move around the membrane creating a “mosaic” pattern
Gated channel protein
Transport proteins that open a “gate” allowing molecules to pass through the cell membrane; has a binding site that is specific for a given molecule or ion
Golgi apparatus
Large organelle that processes proteins and prepares them for use inside and outside the cell
Homogenous
A substance in which all of the parts are the same throughout
Hypertonic
In comparing two solutions of unequal solute concentration, the solution with the higher concentration is called hypertonic
Intermediate filaments
Parts of the cell’s cytoskeleton; provide mechanical support and aid in cell adhesion (sticking cells to other surfaces)
Ion channel
Regulates the flow of ions across the membrane in all cells; this flow does not require energy
Isotonic
Describes a solution of equal solute concentration
Lysosomes
Special vesicles that contain digestive enzymes; break down food like lipids, carbohydrates, proteins, and waste materials into simpler molecules
Matthias Jakob Schlieden
Suggested that all plants are made of cells
Microfilaments
Thinnest if the protein fibers that make up the cytoskeleton of a cell; used for cellular movement such as gliding and contracting
Microtubles
Hollow tubes that are part of the cell’s cytoskeleton; maintain cell shape and provide connections to transport organelles and large molecules in the cell
Nuclear envelope
Membrane surrounding the nucleus of a cell; keeps DNA inside and protects it from materials in the cytoplasm
Nucleus
An organelle in eukaryotic cells that contains the cells chromosomes
Nucleolus
Spherical structure inside the nucleus of a cell where ribosomes are made
Osmosis
The diffusion of water through a thin membrane
Passive transport
Movement of ions or molecules across a membrane down a concentration gradient; it does not require the input of energy
Phospholipid barrier
A thin membrane made of two layers of phospholipids with the fatty acid chains in each layer facing towards the center of the membrane
Ribosome
Molecular structure that translates the DNA messages and uses it to build proteins
Robert Hook
First used the word “cell” to describe the tiny structures he saw when he used a microscope
Rough endoplasmic reticulum
Organelle that is closely associated with the nucleus of a cell and has attached ribosomes; site of protein synthesis
Rudolf Virchow
Stated that all cells come from pre-existing cells
Selectively permeable
Property of a membrane to allow passage of specific molecules
Semipermeable
Describes a membrane that allows certain substances to pass through
Smooth endoplasmic reticulum
Produces lipids, detoxifies chemicals, and transports materials throughout the cell
Solute
A sugarcane that has the ability to be dissolved by a solvent to create a solution
Theodore Schwann
Stated that all animals are made of cells
Transport proteins
Proteins that completely span the cell membrane and allow certain molecules or ions to diffuse across the membrane
Vacuoles
Sacs in a cell’s cytoskeleton that are filled with fluid; can be used to store food for the cell before digestion
Vesicles
Sac-like organelles that store and transport materials in the cell; some are used as chambers for biochemical reactions
