Hierarchy of Structures

Lowest Hierarchy level is at Organelles within a cell. They obtain energy from food

and reproduction.

-Cells with the same function are collected into larger groups called Tissues.

-Tissues are collected into Organs, carry out single task, like oxygenated blood (lungs),

or filter out waste (kidneys).

-Organs work together in systems that perform coordinated large-scale functions,

like nourishing the body (digestive) or protecting the body from attacks (immune).

Cell Parts

Organelles: Cell parts that function within a cell. They coordinate with other organelles

to performs a cell's basic function, like energy processing and waste excretion.

~Examples: Ribosomes, Golgi Apparatus, Mitochondria, The Nucleus.

The Nucleus

-Nucleus: Small structure that contains Chromosomes and Regulates the DNA of a

cell. Defining structure of eukaryotic cells. It is responsible for the passing on of

genetic traits between generations.

-Contains: nuclear envelope, nucleoplasm, a nucleolus, nuclear pores, chromatin, and

ribosomes.

Chromosomes

Highly condensed, threadlike rods of DNA. DNA is genetic material that stores

information about the plant or animal.

Chromatin

Consists of the DNA and Proteins that make up chromosomes.

Nucleolus

Structure contained within the nucleus, consists of proteins. Small, Round, and

does not have a membrane. Involved in protein synthesis, and synthesizes and

stores RNA.

Nuclear Envelope

Encloses the nucleus. Consists of inner and outer membranes made of lipids.

Nuclear Pores

Involved in exchange of material between nucleus and the cytoplasm.

Nucleoplasm

Liquid within the membrane and is similar to cytoplasm.

Cell Membrane

"Plasma Membrane"

-Made of Lipids and Proteins

-Isolates the cell from its external environment while still enabling the cellar to

communicate with the outside environment.

-Consists: Phospholipid bilayer with the hydrophilic ends of the outer layer facing

external environment.

~Cholesterol: Adds stiffness and flexibility

~Glycolipids: Help cell to recognize other cells of the organisms.

~Proteins: Help give cells shape

~Special Proteins: Helps cell communicate with external environment.

~Other Proteins: Transport molecules across membrane

Selective Permeability

With regard to size, charge, and solubility.

-Size: Membrane allows small molecules to diffuse through it. Oxygen and Water

molecules are small and can pass through the cells membrane.

-Charge: Ions on a cells surface either attracts or repels ions. Ions with like charges

are repelled, and ions with opposite charges are attracted to the surface.

-Solubility: Molecules that are soluble in phospholipids can usually pass through the

membrane. Many are not able to diffuse the membrane, and if anything they'll have to

be moved through by active transport and vesicles

Cell Structures

Inside the cell. Contain: Ribosomes, Golgi Apparatus, Vacuoles, Vesicles, Cytoskeleton,

Microtubules, Cytosol, Cytoplasm, Cell Membrane, Endoplasmic Reticulum,

Mitochondria

Ribosomes

Involved in synthesizing proteins from amino acids.

-Make up about a quarter of a cell.

-Some are embedded in the Rough Endoplasmic Reticulum (Rough ER)

Golgi Apparatus

Involved in synthesizing materials like proteins that are transported out of the cell.

~Modifies and Packages proteins secreted from the cell.

-Located near the nucleus and has layers of membranes.