1. Composed of a phospholipid bi-layer. Permeable to polar materials, non-polar materials must pass through channels.
Plasma Membrane:
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.
OSMOSIS
Three forms:◦Diffusion◦Facilitated diffusion (using a pore protein
like water)◦Osmosis (diffusion of water)
Passive Transport- no energy
high
low
Weeee!!!
Three Forms:◦ Protein Pumps- Channel proteins◦ Exocytosis- things exit out of cell◦ Endocytosis- things taken into the cell
Active Transport- needs energy
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.
Transportation of Large Particles
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.\
Nucleus and Cell Control
Master set of directions for making proteins is contained in CHROMATIN- strands of the genetic material DNA.
Cell Control Cont…
Nucleolus organelle within the nucleus that makes ribosomes.
Ribosomes Site where cells produce proteins according to DNA directions
ribosomes
Cell control cont…
For proteins to be made, ribosomes must leave the nucleus and enter the cytoplasm where the DNA blueprints are turned into protein.
CYTOPLASMClear gelatinous fluid within the cell. Ribosomes go through the nuclear envelope into the cytoplasm
Cell control cont…
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.
ASSEMBLY, TRANSPORT AND STORAGE.
Golgi Apparatus: “POST OFFICE” Flattened stack of tubular membranes that packs sorts and delivers proteins to their appropriate destinations with VESICLES.
Assembly storage and transport cont…
Membrane bound compartments for temporary storage of enzymes or materials needed by the cell. Usually water in a plant
Vacuoles and storage
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.
Lysosomes and Recycling
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.
Peroxisomes
EVERYTHING we have talked about within the cell needs energy. In humans this is provided by
◦ MITOCHONDRIA
ENERGY TRANSFORMERS
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.
Mitochondria- all cells
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!
Mitochondria cont…
Cytoskeleton- framework for the cell. Initially thought that the organelles floated in cytoplasm.
Network of 1.Microtubules-thin Hallow cylinders madeOf protein.2. Microfilaments- smallSolid protein fibers
Organelles for SUPPORT and LOCOMOTION.
Forms a SCAFFOLD that◦ Maintains cell shape◦ Anchors and supports organelles◦ Highway system for organelles
Cytoskeleton cont…
Centrioles: Cell organelles found in Animals and most
protists. Occur in pairs. Made of microtubules Important to cell division
Locomotion
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
Cilia and Flagella
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?
Structure and Function