Hierarchy of Structures
Lowest Hierarchy level is at Organelles within a cell. They obtain energy from food and reproduction.
-Cells with the same
... [Show More] 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.
Vacuoles
Sacs used for storage, digestion, and waste removal.
-Plant: Has one large vacuole
-Animal: Has small, sometimes numerous vacuoles.
Vesicles
Small organelle within a cell, has a membrane.
-Functions: Moving materials within a cell.
Cytoskeleton
Consist of microtubules that help shape and support the cell.
Microtubules
Part of cytoskeleton.
-Help support the cell.
-Made of proteins
Cytosol
Liquid materials in the cell. Mostly water, also contains floating molecules.
Cytoplasm
Refers to Cytosol and the substructures (organelles) found within the plasma membrane, but not within the nucleus.
Cell Membrane
Acting as a barrier. Helps keep cytoplasm in and substances located outside the cell out.
-Helps determine what is allowed to exit and enter.
Endoplasmic Reticulum
Two Types:
-Rough ER: Has ribosomes on surface.
~Functions: Manufacture lysosomal enzymes, Manufacture of secreted proteins. (Protein production, protein folding, quality control, and despatch)
-Smooth ER: Has no ribosomes.
~Functions: Manufacture Lipids (fat), Metabolism, Steroid Hormone production (adrenal cortex and endocrine glands), Helps liver detox.
-Tubular Network that comprises the transport system of a cell. It is fused to the nuclear membrane and extendsthrough cytoplasm to the cell membrane.
Mitochondria
Vary in terms of size and quantity. Has various functions.
-Functions: Production of Cell Energy (ATP) (Main function), Cell Signaling (Communications are carried out), Cell Differentiation (Cell transforms into a cell with more specialized purpose), Cell Cycle and Growth Regulation (Growth and Death, Reproduction).
-Inner and Outer membrane:
~Inner: Encloses the matrix. Contains mtDNA and ribosomes.
~Between the 2 Membranes: Cristae (Folds). Chemical reactions occur here
that release energy, Control Water Levels in cells, and Recycle and Create Proteins and Fats.
-Aerobic Respiration: Occurs in Mitochondria.
Animal Cell Structure
Contains: Centrosomes, Centriole, Lysosome, Cilia, Flagella Centrosome
Pair of centrioles located at right angles to each other and surrounded by protein.
-Involved in Mitosis and Cell Cycle
Centriole
Cylinder-shaped structures near the nucleus.
-Involved in Cellular Division
-Each cylinder consist of 9 Groups of 3 Microtubules. Occurs in pairs.
Lysosome
-Functions: Digest proteins, lipids, and carbohydrates. Also transports undigested substances to the membrane do they can be removed. Shape depends on material being transported.
Cilia
Appendages extending from the surface of the cell.
-Moves the cell and results in fluid being moved by the cell. Flagella
Tail-like structures on cell that use whip-likemovements to help move the cell. Longer than Cilia. Only has one or a few flagella.
Cell Cycle
The process by which a cell reproduces which involves cell growth, duplication of genetic material, and cell division.
-Complex organisms: Use the cell cycle to replacecells as they lose their functionality and wear out.
-In Animals: Cell Cycle can take 24 hours.
-Human Skin Cells: Constantly reproducing.
-2 Ways for Cell Reproduction: Mitosis and Meiosis
Cell differentiation
Determines the different cell types
-When less-specialized cell becomes a more-specialized cell. Process is controlled by genes of each cell among a group of cells known as a zygote.
-Cell builds certain proteins and other pieces that set it apart as a specific type of cell.
~Example: Gastrulation (early phase in embryonic development in animals) Mitosis
Events that occur: Interphase, Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis.
Interphase
Cell prepares for division by replicating its genetic and cytoplasmic material.
-Further divided into G1, S, G2 (Meiosis)
Prophase
-Chromatin thickens into chromosomes and the nuclear membrane begins to disintegrate.
-Pairs of Centrioles move to opposite sides and spindle fibers begins to form.
-Mitotic Spindle moves chromosomes around wishing the cell.
Metaphase
Spindle moves to the center of the cell and chromosome [Show Less]