Cell Review Chapter 3

Lindsay

Cells are best described and studied by Robert Hooke. When he studied the cells he used a early light microscope. Hooke looked at the dried cork under this microscope. After looking at hundreds of empty chamber like pictures, he named them calls.

Cell Theory

Cytology is the study of the structure and

function of the cell. There are two other ways cells are revealed

than the one Hooke used. Another one is the transmission electron microscopy, in this particular scope electrons pass through a ultrathin section to strike a photographic plate. The last one is the scanning electron microscopy when electron bounce off exposed surfaces to create a SEM.

Extracellular fluid

• Watery medium • How a cell

survives• Physiological

systems• the cell

membrane separates the cell membrane contents.

Intracellular Fluid

• Also known as cytosol

• Dissolves nutrients, ions, soluble and insoluble proteins, and waste products.

Also known as the plasma membrane. The cell membrane forms the otter boundary

of the cell. The layer is made up of the phospholipids,

proteins, glycolipids, and cholesterol.

Cell Membrane

The cell uses its environment in many ways,

one is to obtain water and also nutrients from the environment.

Also the boundary or barrier from the cell and its environment its called the plasma membrane.

A plasma membrane, is the outer boundary of the cell.

The Cell and its Environment

Nonmembranous organelles are always in

contact with the cytosol. The cells Nonmembranous organelles are the

cytoskeleton, microvilli, centrioles, cilia, and flagella, also the ribosomes.

Nonmembranous Organelle

This organelles are surrounded by a lipid

membrane that create space between the cytosol from the extracellular fluid.

They are bound by units somewhat like the cell membrane.

Membranous Organelles

Cytoskeleton- Strength movement of cellular

structures and materials. Microvilli- absorption of extracellular materials Centriole- Movement of chromosomes during

cell division. Cilia- Movement of materials over surface Ribosome- Protein synthesis.

Nonmembranous Organelles

Mitochondria-produces about 95 percent of the energy needed to keep

a cell alive Nucleus- control of metabolism, storage and processing genetic

information Endoplasmic reticulum- secretory protein synthesis, lipid and

carbohydrate synthesis. Golgi Apparatus- Storage, alteration, and packing of secretory

products and lysosomes. Lysosomes- Intracellular removal of damaged organelles or of

pathogens Peroxisomes- Neutralization of toxic compounds

Membranous Organelles

The sun is the main component in giving the

cell fuel to power all of their functions. Cells also get energy and power from the

mitochondria Mitochondria- are small organelles that have

an unusual double membrane. Having both of these energizers that gives the

cell all of its energy to fuel all of its functions.

Cell Power

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omy/cell/cell_game.htm

Nucleus Game!

The nucleus is the control center for the cell,

most cells only have one nucleus. The nucleus directs processes that take in the

cytosol. Also the nucleus takes in information about all

of the conditions and activities from the cell.

Nucleus

Cellular reproduction is done by the process of cell division. They are

six stages to the cell cycle. The first step is the G1 phase this happens when the cell starts to

divide Second step is S phase this is when the cells DNA replicates, also the

synthesis of histones. Next is G2 is protein synthesis From this point it turns into mitosis, which has 4 stages. Prophase,

metaphase, anaphase, and telophase. Cytokinesis- in a separate process from division of the genetic

materials in mitosis. During this time, the two daughter cells are starting to be formed.

At the end of the cell life cycle, daughter cells are formed. They are each smaller to its parents but are two genetically identical daughter cells.

Cell Life & Cycle

The transmembrane potential is the characteristic of all

living cells because it results from the active and passive properties of their cell membranes.

Although the transmembrane potential is not visible through a microscope, it is just as an important as any other structural characteristic or organelle.

Cell functions that involve the cell membrane involve the transmembrane potential. Also because the transmembrane can magnify a stimulus, it greatly increases the cells sensitivity to its environment.

The mechanisms that maintain the transmembrane potential is the ions that are rushed into or out of the cell, but it does not depend on the size or mature of the stimulus.

Transmembrane Potential

Most cells in the body are firmly attached to other cells or to

extracellular protein fibers. The attached occur at the cell junctions that are not involved in membrane flow. There are four types of cell junctions-

Gap Junctions- are two cells are held together by an interlocking of membrane proteins.

Tight Junctions- there is a partial fusion of the lipid portions of the two cell membranes.

Intermediate Junctions- the opposing cell membranes, while remaining distinct, are held together by a thick layer of proteoglycan.

Desmosomes- there a very thin proteoglycan layer between the opposing cell membranes.