Chapter 2 Cells, Tissues, Organs, and organ Systems of Animals

What are Cells? Cells are the smallest independent units of life. Cells are the smallest independent units of life. Prokaryotes- simple, lacks a nucleus Prokaryotes- simple, lacks a nucleus Eukaryotes- complex, has true nucleus Eukaryotes- complex, has true nucleus Plasma Membrane- outer boundary of cell Plasma Membrane- outer boundary of cell Cytoplasm- fluid outside the nucleus, maintains cell structure Cytoplasm- fluid outside the nucleus, maintains cell structure Nucleus- cell control center Nucleus- cell control center

Why Are Most Cells Small? One reason for the small size of cells is that the ratio of the volume of the cell’s nucleus to the volume of its cytoplasm must not be so small that the nucleus cannot control the cytoplasm. One reason for the small size of cells is that the ratio of the volume of the cell’s nucleus to the volume of its cytoplasm must not be so small that the nucleus cannot control the cytoplasm.

Cell Membranes Structure of cell Membranes Structure of cell Membranes Define the following: Define the following: Phospholipids- Phospholipids- Cholesterol- Cholesterol- Membrane Proteins- Membrane Proteins- Carbohydrates- Carbohydrates- Functions of Cell Membranes Functions of Cell Membranes Regulate material moving into and out of the cell Regulate material moving into and out of the cell Separate the inside from the outside Separate the inside from the outside Separates the organelles Separates the organelles Provide a large surface area for chemical reactions Provide a large surface area for chemical reactions Separate cells from one another Separate cells from one another Are sites for specific cell identification markers Are sites for specific cell identification markers

Movement Across Membranes Passive Transport Passive Transport Simple Diffusion Simple Diffusion Facilitated Diffusion Facilitated Diffusion Osmosis Osmosis Filtration Filtration Active Transport Active Transport Endocytosis Endocytosis Exocytosis Exocytosis

Passive Transport Passive mechanisms is spontaneous and does not require cellular energy. Passive mechanisms is spontaneous and does not require cellular energy. It includes simple diffusion, facilitated diffusion, osmosis, and filtration. It includes simple diffusion, facilitated diffusion, osmosis, and filtration.

Simple Diffusion No cell energy is needed Molecules spread out randomly from area of higher concentration to area of lower concentration. Example: A frog inhales air containing oxygen, which moves into the lungs and then diffuses into the bloodstream.

Facilitated Diffusion Carrier (transport) proteins in a plasma membrane temporarily bind w/ molecules and help them pass across the membrane. Carrier (transport) proteins in a plasma membrane temporarily bind w/ molecules and help them pass across the membrane. Other proteins form channels through which molecules move across the membrane. Other proteins form channels through which molecules move across the membrane. Examples: Glucose in the gut of a frog combines w/ carrier protein to pass through the gut cells into the bloodstream. Examples: Glucose in the gut of a frog combines w/ carrier protein to pass through the gut cells into the bloodstream.

Osmosis Water molecules diffuse across selectively permeable membranes from area of higher concentration to area of lower concentration. Water molecules diffuse across selectively permeable membranes from area of higher concentration to area of lower concentration. Example: water molecule moves into a frog’s red blood cell when the concentration of water molecules outside the blood cell is greater than in the inside. Example: water molecule moves into a frog’s red blood cell when the concentration of water molecules outside the blood cell is greater than in the inside.

Filtration Essentially protein- free plasma moves across capillary walls due to a pressure gradient across the wall Essentially protein- free plasma moves across capillary walls due to a pressure gradient across the wall Example: A frog’s blood pressure forces water and dissolved wastes into the kidney tubules during urine formation. Example: A frog’s blood pressure forces water and dissolved wastes into the kidney tubules during urine formation.

Active Transport Specific carrier protein in the plasma membrane bind with molecules or ions to help them across the membrane against a concentration gradient Specific carrier protein in the plasma membrane bind with molecules or ions to help them across the membrane against a concentration gradient Cellular energy required Cellular energy required Example: Sodium ions move from inside to the neurons of the sciatic nerve of a frog (the sodium-potassium pump) to the outside of the neurons. Example: Sodium ions move from inside to the neurons of the sciatic nerve of a frog (the sodium-potassium pump) to the outside of the neurons.

Endocytosis Pinocytosis: The plasma membrane encloses small amounts of fluid droplets and takes them into the cell. Pinocytosis: The plasma membrane encloses small amounts of fluid droplets and takes them into the cell. Example: the kidney cells of a frog take in fluid to maintian fluid balance Example: the kidney cells of a frog take in fluid to maintian fluid balance Phagocytosis: The plasma membrane forms a vesicle around a solid particle or other cell and draws it into the phagocytic cell. Phagocytosis: The plasma membrane forms a vesicle around a solid particle or other cell and draws it into the phagocytic cell. Example: the white blood cells of a frog engulf and digest harmful bacteria. Example: the white blood cells of a frog engulf and digest harmful bacteria. Receptor-mediated endocytosis: The plasma membrane forms a vesicle around a solid particle or other cell and draws it into the phagocytic cell. Receptor-mediated endocytosis: The plasma membrane forms a vesicle around a solid particle or other cell and draws it into the phagocytic cell. Example: The intestinal cells of a frog take up large molecules from the inside of the gut. Example: The intestinal cells of a frog take up large molecules from the inside of the gut.

Exocytosis The movement of material out of a cell. A vesicle fuses with the plasma membrane and expels particles or fluids from the cell across the plasma membrane. The reverse of endocytosis. The movement of material out of a cell. A vesicle fuses with the plasma membrane and expels particles or fluids from the cell across the plasma membrane. The reverse of endocytosis. Example: The sciatic nerve of a frog releases a chemical (neurotansmitter) Example: The sciatic nerve of a frog releases a chemical (neurotansmitter)

Cytoplasm, Organelles, and Cellular Components Define and list the function of each of the following: Define and list the function of each of the following: Cytoplasm: jelly like fluid that fills and supports the cell. Cytoplasm: jelly like fluid that fills and supports the cell. Ribosomes: Protein Workbenches Ribosomes: Protein Workbenches Endoplasmis Reticulum: Production and Transport Endoplasmis Reticulum: Production and Transport Golgi Apparatus: Packaging, Sorting, and Export Golgi Apparatus: Packaging, Sorting, and Export Lysosomes: Digestion and Degradation Lysosomes: Digestion and Degradation Mitochondria: Power Generators Mitochondria: Power Generators Cytoskeleton: Microtubules, Intermediate Filaments, and Microfilaments Cytoskeleton: Microtubules, Intermediate Filaments, and Microfilaments Cilia and Flagella: Movement Cilia and Flagella: Movement Centrioles and Microtubule-Organizing Centers Centrioles and Microtubule-Organizing Centers Vacuoles: Cell Maintainance Vacuoles: Cell Maintainance Vaults: A Newly Discovered Organelle Vaults: A Newly Discovered Organelle

The Nucleus: Information Center Nuclear Envelope: Gateway to the Nucleus Nuclear Envelope: Gateway to the Nucleus Chromosomes: Genetic Containers Chromosomes: Genetic Containers Nucleolus: Preassembly Point for Ribosome Nucleolus: Preassembly Point for Ribosome

Levels of Organization in Various Animals Protoplasmic organization Protoplasmic organization Cellular organization Cellular organization Tissue level Tissue level Organ level Organ level Organ System level Organ System level

Tissues Epithelial Tissue: Many Forms and Functions Epithelial Tissue: Many Forms and Functions Connective Tissue: Connection and Support Connective Tissue: Connection and Support 2 types: Loose & Fibrous 2 types: Loose & Fibrous Name the different tissues & there location. Name the different tissues & there location. Muscle Tissue: Movement Muscle Tissue: Movement Nervous Tissue: Communication Nervous Tissue: Communication

Organs Functional units of tan animal’s body that are made up of more than 1 type of tissue. Functional units of tan animal’s body that are made up of more than 1 type of tissue. Give 7 Examples. Give 7 Examples.

Organ Systems An association of organ togerther performs an overall function. An association of organ togerther performs an overall function. Give 11 examples. Give 11 examples.