Biology - Ch. 4

Front 1

Cell Theory

Back 1

1) Cells are the fundamental units of life
2) All organisms are composed of cells
3) All cells come from preexisting cells

Front 2

Surface Area-to-Volume Ratio

Back 2

1) The volume of a cell determines the amount of chemical activity it carries out per unit of time
2) The surface area of a cell determines the amount of substances the cell can take in from the outside environment and the amount of waste products it can release to the environment

Front 3

Resolution

Back 3

The distance apart two objects must be in order for the eye to distinguis them as seperate

Front 4

Plasma Membrane

Back 4

Composed of a phospholipid bilayer, with the hydrophilic "heads" of the lipids facing the cell's aqueous interior on one side of the membrane and the extracellular environment on the other

Front 5

Prokaryotes

Back 5

Archaea and Bacteria in which their cells do not typically have membrane-enclosed internal compartments.

Front 6

Nucleus

Back 6

A special membrane-enclosed compartment that contains the genetic material of eukaryotic cells

Front 7

Nucleoid

Back 7

Contins the hereditary material of the cell

Front 8

Cytoplasm

Back 8

The rest of the material enclosed in the plasma membrane. Composed of two compnents: the more fluid cytosol and insoluble suspended particles

Front 9

Cytosol

Back 9

Consists mostly of water that contains dissolved ions, small molecules, and soluble macromolecules

Front 10

Ribosomes

Back 10

Complexes of RNA and are the sites of protein synthesis

Front 11

Nucleolus

Back 11

Begins the assembly of ribosomes from RNA and specific proteins

Front 12

Endomembrane System

Back 12

Includes two main components, the endoplasmic reticulum and the Golgi apparatus

Front 13

Endoplasmic Reticulum

Back 13

A system of membranous tubes and flattened sacs found in the cytoplasm of eukaryotes

Front 14

Rough Endoplasmic Reticulum

Back 14

1) As a compartment, the RER segregates certain newly synthesized proteins away from the cytoplasm and transports them to other locations in the cell
2) While inside the RER, proteins can be chemically modified so as to alter their function and eventual destination

Front 15

Smooth Endoplasmic Reticulum

Back 15

1) It is responsible for chemically modifying small molecules taken in by the cell
2) It is the site for the hydrolysis of glycogen in animal cells
3) It is the site for the synthesis of lipids and steroids

Front 16

Golgi Apparatus

Back 16

1) It receives proteins from the ER and may further modify them
2) It concentrates, packages, and sorts proteins before they are sent to their cellular or extracellular destinations
3) It is where some polysaccarides for the plant cell wall are synthesized

Front 17

Lysosomes

Back 17

A membrane-enclosed organelle found in eukaryotic cells. Lysosomes contain a mixture of enzymes that can digest most of the macromolecules found in the rest of the cell

Front 18

Mitochondria

Back 18

Contains the enzymes of the citric acid cycle, the respiratory chain, and oxidative phosphorylation

Front 19

Chloroplasts

Back 19

An organelle bounded by a double membrane containing the enzymes and pigments that perform photosynthesis. The occur only in eukaryotes

Front 20

Thylakoids

Back 20

A flattened sac within a chloroplast.

Front 21

Peroxisome

Back 21

Organelles taht collect the toxic peroxides that are the unavoidable by-products of cellular chemical reactions

Front 22

Glyoxysome

Back 22

The sites where stored lipids are converted into carbohydrates for transport to growing cells

Front 23

Vacuoles

Back 23

1) Storage
2) Structure
3) Reproduction
4) Digestion

Front 24

Cytoskeleton

Back 24

1) Supports the cell and maintains its shape
2) Provides for various types of cellular movement
3) Positions organelles within the cell
4) Some of its fibers act as tracks or supports for motor proteins, which move organelles within the cell
5) Interacts with extracellular structures, helping to anchor the cell in place

Front 25

Microfilaments

Back 25

1) Help the entire cell or parts of the cell to move
2) Determine and stabilize cell shape

Front 26

Intermediate Filaments

Back 26

1) Stabilize cell structure
2) Resist tension

Front 27

Microtubules

Back 27

1) Form a rigid internal skeleton for some cells
2) Act as a framework along which motor proteins can move structures within the cell

Front 28

Motor Proteins

Back 28

Specialized molecules that use energy to change their shape and move

Front 29

Cilia

Back 29

Hairlike organelle used for locomotion by many unicellular organisms and for moving water and musuc by many multicellular organisms. Generally shorter than a flaggellum

Front 30

Centrioles

Back 30

A paired organelle that helps organize the microtubules in animal and protist cells during nuclear division

Front 31

Cell Wall

Back 31

1) Provides support for the cell and limits its volume by remaining rigid
2) Acts as a barrier to infection by fungi and other organisms that can cause plant diseases
3) Contributes to plant form by growing as plant cells expand

Front 32

Plasmodesmata

Back 32

A cytoplasmic strand connecting two adjacent plant cells

Front 33

Extracellular Matrix

Back 33

1) Holds cells togeether in tissues
2) Contributes to the physical properties of cartilage, skin, and other tissues
3) Helps filter materials passing between different tissues
4) Helps orient cell movements during embryonic development and during tissue repair
5) Plays a role in chemical signaling fromm one cell to another

Front 34

Collagen

Back 34

The most abundant protein in mammals, constituting 25 percent of the protein in the human body

Front 35

Proteoglycans

Back 35

A glycoprotein containing a protein core with attached long, linear carbohydrate chains

Front 36

Endosymbiosis

Back 36

Two species living together, with one living inside the body of the other

Front 37

Endosymbiosis Theory

Back 37

The theory that the eukaryotic cell evolved via the engulfing of one prokaryotic cell by another