Tiara

Chapter 3 Review Guide

The Cell Theory States:

• The cell is the basic unit of life.

• All living organisms are composed of cells, they may multicellular or unicellular.

• Cells arise from pre-existing cells.

More Modern Concepts State:

• Energy flow occurs within the cells.

• DNA is passed from cell to cell.

• All cells have the same basic chemical composition.

Cell Theory

Actually, intracellular is really called

Cytosol. Cytosol contains dissolved

nutrients, ions, waste products, and soluble

and insoluble proteins.

The cell membrane keeps the

intracellular fluid away from the

extracellular fluid.

Intracellular Fluid Vs.

ExtracellularFluid

Extracellular fluid is what our cell

floats around and about in. It’s a

watery substance, and like it was

previously stated, the cell membrane

separates the extracellular from the intracellular

fluid.

STRUCTURE: The cell membrane is

basically a wall that separates the interior

of cells, from the outside atmosphere. It is

selectively permeable to organic molecules

and ions.

It protects the cell from the outside forces,

and consists of the lipid bilayer with

embedded proteins/

IMPORTANCE: The cell membrane anchors

the cytoskeleton to provide a shape to the

cell. It also attaches to the extracellular

matrix and other cells to form tissues.

Cell Membrane

Cells interact with their environment through many ways. The cells needs to obtain

nutrients from the environment, maintain water balance with their surroundings and to remove the waste materials from within the

cell. The plasma membrane keeps a boundary between any cell and its environment.

Cells and Their Environment

Non-Membranous Membranous The membranous organelles are listed below:

Mitochondria, Nucleus, endoplasmic reticulum, Golgi apparatus, lysosomes, and

peroxisomes.

MITOCHONDRIA: small organelles that have an unusual double membrane.

NUCLEUS: the control center for cellular operations.

ENDOPLASMIC RETICULUM: a network of intracellular membranes.

GOLGI APPARATUS: consists of flattened membrane discs, called saccules, and contains of five to six of them.

LYSOSOMES: vesicles that are filled with digestive enzymes.

PEROXISOMES: are smaller than lysosomes and carry a different group of enzymes.

The non-membranous organelles are the following:

Cytoskeleton, microvilli, centrioles, cilia, flagella, and ribosomes.

CYTOSKELETON: is an internal protein framework that gives the cytoplasm strength, and flexibility.

MICROVILLI: small, finger-shaped projections of the cell membrane.

CENTRIOLES: are cylindrical structures composed of short microtubules.

CILIA: contain nine pairs of microtubules that surround a central pair.

FLAGELLA: resemble cilia, but larger, they move a cell through surrounding fluid.

RIBOSOMES: small, dense structures that cannot be seen clearly with the light microscope.

Organelles

The nucleus is the control center for

cellular operations. The nucleus directs

processes that take place in the cytosol

and must receive information about the

conditions and activities in the cytosol.

The nucleus has many parts surrounding

itself, including: the nuclear envelope,

nuclear space, nuclear pores,

nucleoplasm, nucleoli, and nucleosome.

Most cells have one nucleus, but some

are an exception and have many nuclei.

The Nucleus

Cell Life Cycle

How Cells DivideCells divide through a process

called Mitosis and Meiosis. People know cell division, and they mean mitosis, which is the

process of making new body cells. Meiosis is the cell division that makes sperm and egg cells.

INTERPHASEG1: a cell that is going to divide first.S-Phase: cell duplicates its chromosomes for next 6-8 hours.G2: last minute protein synthesis.

MITOSISProphase: begins when chromosomes coil tightly together and become visible as individual structures.Metaphase: chromosomes move to a narrow central zone called metaphase plate.Anaphase: chromatid pairs separate and daughter chromosomes move toward opposite ends of cell.Telophase: Nuclear membranes form, nuclei enlarge, and chromosomes gradually uncoil.Cytokinesis: separation of daughter cells.

Transmembrane

potential is the

difference in

voltage between

the interior and

exterior of a cell.

Trans Membrane Potential