Chapter 3 Cell definitions

differentiated

Cells that have developed specialized characteristics

Nucleus

Contains genetic material for replication and differentiation, directs cell's activities

Command center of cell

Cytoplasm

Consists of organelles, with specific functions, suspended in a liquid called cytosol

Jelly-like fluid that fills up the space between organelles, carries nutrients to all organelles

3 major parts of the Cell

Nucleus, cytoplasm, cell membrane

Chromotin

Consists of cell chromosomes, each containing DNA wound around proteins

stores information for protein synthesis

Nucleolus

Site where ribosomes are produced

Dense body of RNA protein

Intermediate Filaments

Intertwined protein fibers that provide support and strength

nuclear envelope

Double layer membrane between the nucleus and the cytoplasm

contians nuclear pores that allow passage of certain substances

Plasma membrane

lipid bilayer in which proteins are embedded

Cytoplasm

semifluid matrix that contains the nucleus and other organelles

Golgi complex

Collects, packages, and distributing molecules such as lipids and proteins manufacturing in the cell

lysosome

Vesicle that breaks down macromolecules and digests worn out cell components (wastes, cell parts, and foreign invaders)

Contain enzymes that digest proteins, carbohydrates, nucleic acids, bacteria, debris, worn out cell parts

Mitochondrion

organelle in which energy is extracted from food during oxidative metabolism

Breaking down food for ATP

Secretory Vesicle

Vesicle fusing with the plasma membrane, releasing materials to be secreted from the cell

Centriole

Complex assembly of microtubules that occur in pairs

Cytoskeleton

Supports organelles and cell shape and plays a role in cell motion

Microtubule

Tube of protein molecules present in cytoplasm, centrioles, cilia, and flagella

Actin Filament

Twisted protein fibers that are responsible for cell movement

Smooth Endoplasmic Reticulum

System of internal membranes that aids in the manufacture of carbohydrates and lipids.

Rough Endoplasmic reticulum

internal membranes studded with ribosomes that carry out protein synthesis

nuclear pore

Opening embedded with proteins that regulates passage into and out of the nucleus

ribosomes

small complexes of RNA and protein that are the sites of protein synthesis

Found in the cytoplasm and endoplasmic reticulum

the organelle in which amino acids are hooked together to make proteins

Peroxisome

Vesicle that contains enzymes that carry out particular reactions, such as detoxifying potentially harmful molecules

contain enzymes and hydrogen peroxide that digest lipids and alcohol

Endoplasmic Reticulum

Complexly folded organelle that is responsible for regulating and producing proteins and other molecules, located near the nucleus

the organelle that makes lipids, breaks down drugs and other substances, and packages proteins for golgi complex

Cell membrane

Barrier around an animal cell which allows certain kinds of materials in and out of the cell

Selectively Permeable
Signal Transduction (permits cell to receive and respond to messages)
Consists mainly of lipids and proteins

Chloroplast

The organelle that uses the energy of sunlight to make food

large central Vacole

The organelle that stores water and other materials

Microfilaments

tiny rods of actin
Provide cellular movement, such as muscle contraction

Microtubules

Larger tubes of tublin
rigidity maintains cell shape
make up cilia, flagella, and centrioles,
help move organelles

Intermediate Filaments

Composed of several proteins
a cytoskeletal structure
support nuclear envelope

Phospholipid Bilayer

Cell membrane framework

Cholestrol

stabilizes membrane, helps keep it impermeable to water-soluble substances

Integral proteins

permanently embedded within the cell membrane

Peripheral membrane proteins

attached to the surface of the membrane at different times

types: Selectins, adhesions, receptor proteins, integrins

Protein Receptors

Respond to extracellular signals

Protein pores, channels, and carriers

transport small molecules and ions; transduce signals

enzymes

catalyze chemical reactions

cellular adhesions molecules

enable cells to stick to each other

cystic fibrosis

production of thick mucus which causes difficulty breathing,clogged pancreas, salty sweat

Microvilli

Tiny extensions ofcell membrane
Composed of actin
Increase surface area for absorption

Melas

Mutant gene in DNA of mitochondria.
Person cannot extract maximum energy from nutrients

effects of tonicity on cells

when a red blood cell is placed in a hypotonic solution water enters ge cell by osmosis

when a red blood cell is placed in an isotonic solution water moves into and out of the cell at the same rate. No net water movement occurs and the cell shape remains normal.

When a red blood cell is placed in a hypertonic solution water moves by osmosis out of the cell and into the colution resulting in shrinkage

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

Movement of a substance into the cell inside a vesicle
Substances too large to enter by other methods can entercell this way

Exocytosis

Process by which a cell releases large amounts of material

Active Transport

Movement of substances across a membrane from region of lower concentration to region of higher concentration (against concentration gradient)

secondary active transport

a carrier protein uses aNa+ gradient to transport another substance across a cellmembrane; this process does not require ATP energy43

Sodium-Potassium transport

A transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell.

Na+ high outside cell K+ high inside cellPump helps to maintain cellular homeostasis

Pinocytosis

membrane engulfs droplets of liquid

Phagocytosis

membrane engulfs solid particles

Receptor-mediated endocytosis

membrane engulfs specific substances, which have bound to receptor proteins on the membrane

Interphase

Growth of cell, DNA replication, maintenance of normal functions

Mitosis

Division of nucleus

Cytokinesis

Division of cytoplasm

Prophase

Chromatin condenses to form chromosomes, centrioles moveto opposite sides of cytoplasm, nuclear envelope and nucleolus disperse

Metaphase

Spindle fibers from centrioles attach to chromosomes andalign them midway between centrioles

Anaphase

Chromosomes separate and move in opposite directionstoward centrioles as the spindle fibers shorten

Telophase

Chromosomes return to chromatin structure, nuclearenvelope forms around each chromosome set, and nucleoli become visible

Differentiation

process of specialization of cells

Stem Cell

Can differentiate as any of many cell types

Progenitor Cell

Can divide to become any of a restricted number of cells;called a "committed" cell

Totipotent

Daughter cells that can specialize to become anycell type, such as fertilized egg, cells of early embryo

Pluripotent

Daughter cells that can become a limited numberof cell types, such as stem cells of later development,progenitor cells

Apoptosis

Programmed cell death
Removes webbing between fetal fingers and toes
Normal part of development
A continuous, stepwise process
Protective, peels away damaged skin cells after sunburn

Necrosis

Not a normal process
Cell death from damage