1. Composed of a phospholipid bi-layer. Permeable to polar materials, non-polar materials must pass through channels.
online.com/Objects/ViewObject.aspx?ID=AP110 1
Osmosis- diffusion of water across a selectively permeable membrane. Review: diffusion is the movement of materials from a area of high concentration to an area of low concentration. Concentration gradient: If 2 solutions are separated by a semi permeable membrane the water will flow to the side where water concentration is the lowest.
Three forms: ◦ Diffusion ◦ Facilitated diffusion (using a pore protein like water) ◦ Osmosis (diffusion of water) high low Weeee!!!
Three Forms: ◦ Protein Pumps- Channel proteins ◦ Exocytosis- things exit out of cell ◦ Endocytosis- things taken into the cell high low This is gonna be hard work!!
Exocytosis- expulsion or sercretion of large molecules. Ex. Waste Endocytosis- Cell surrounds and takes in material from environment.
Leader of the cell b/c it contains the directions to make proteins EVERY part of the cell depends on protein Covered by a nuclear envelope or membrane separating the nucleus from the cytoplasm.\
Master set of directions for making proteins is contained in CHROMATIN- strands of the genetic material DNA.
Nucleolus organelle within the nucleus that makes ribosomes. Ribosomes Site where cells produce proteins according to DNA directions ribosomes
For proteins to be made, ribosomes must leave the nucleus and enter the cytoplasm where the DNA blueprints are turned into protein. CYTOPLASM Clear gelatinous fluid within the cell. Ribosomes go through the nuclear envelope into the cytoplasm
1. ENDOPLASMIC RETICULUM- Site of cellular chemical reactions (metabolism) Smooth ER- has no ribosomes and looks looks smooth. Rough ER- studded with ribosomes and and and is therefore the site of protein synthesis.
Golgi Apparatus: “POST OFFICE” Flattened stack of tubular membranes that packs sorts and delivers proteins to their appropriate destinations with VESICLES.
Membrane bound compartments for temporary storage of enzymes or materials needed by the cell. Usually water in a plant
Lysosomes- organelles containing digestive enzymes (lyse= to break). Breaks down worn out organelles, food particles, viruses, bacteria. Membrane important to protect cell from being digested. Can fuse with vacuole and digest its contents.
Detoxify harmful substances that enter the cell. Seen especially in kidney and liver Contain peroxidase and catalase (some chemical reactions in the body create hydrogen peroxide which is toxic to cells. Peroxidase breaks this down.
EVERYTHING we have talked about within the cell needs energy. In humans this is provided by ◦ MITOCHONDRIA
Membrane bound organelles in plants and animals that transform energy for the cell. Energy is stored in the bonds of other molecules that cell organelles can easily access as needed.
Outer membrane Inner membrane highly folded to increase surface area for storage of energy molecules. Muscle cells have up to 2000 mitochodria in one cell!
Cytoskeleton- framework for the cell. Initially thought that the organelles floated in cytoplasm. Network of 1.Microtubules-thin Hallow cylinders made Of protein. 2. Microfilaments- small Solid protein fibers
Forms a SCAFFOLD that ◦ Maintains cell shape ◦ Anchors and supports organelles ◦ Highway system for organelles
Centrioles: Cell organelles found in Animals and most protists. Occur in pairs. Made of microtubules Important to cell division
Made of microtubules that aide the cell in locomotion and feeding. Major means of locomotion in unicellular organisms. Cilia- short, hair-like ◦ Rowboat motion Flagella- long whip-like movement
Desmosomes ◦ Fibrous connections between cells
Gap junctions- connections through a channel.
Tight Junctions- cells tied together
1. If the liver stores and releases glycogen (glucose) what type of organelles would it have a lot of? 2. What organelle would a muscle need a great deal of? 3. The adrenal gland produces hormones (which are made of protein and lipids). What organelle/s would it have a lot of?