Cells vary greatly in SIZE and STRUCTURE
Cells have 3 main parts
The cell membrane is SELECTIVELY PERMEABLE = controls what enters and leaves the cell, it this its main function.
The cell membrane is a double layer of phospholipids with embedded proteins. Sketch the membrane to remember what it looks like.
CYTOPLASM - the area between the plasma membrane and nucleus. Where most metabolic reactions/activities take place.
(Review) What is metabolism?
The cytoplams many structures called ORGANELLES ("little organs")
ENDOPLASMIC RETICULUM (E.R.) - complex system or network of interconnected
membranes, canals, or channels.
A. Rough ER - where ribosomes are located
Ribosomes function to:
B. Smooth ER - no ribosomes, where lipid synthesis takes place
2. GOLGI APPARATUS (BODIES) - series of flattened membranes
The droplets on the edges of the G.A. are vesicles
3. MITOCHONDRIA (-ion = sing.) - the "powerhouse" of the cell
This process is called CELLULAR RESPIRATION
What does respiration have to do with metabolism?
4. LYSOSOMES -. Contain powerful digesting enzymes, sometimes called the "suicide sac"
What is the purpose of enzymes?
What organ of your body is most like the lysosome?
5. CENTROSOME (central body) -Composed of 2 "cylinders" called CENTRIOLES ( which lie perpendicular to each other)
Involved in cell reproduction - SPINDLE forms from the centrioles
What is the purpose of the spindle?
Sketch the spindle and the centrioles.
Made of microtubules and microfilaments that give the cell support and shape.
What two structures function in movement? Describe or sketch them
- directs the activities of a cell.
- Contains GENETIC material = chromatin which condenses to form chromosomes (made of DNA)
- has a nucleolus which makes ribosomes
- tiny pores in the nuclear membrane allows RNA to leave the nucleus
What part of the cell is most like the:
2. Circulatory System
LABEL THE CELL
DIFFUSION - molecules
move spontaneously (no cellular energy used) from an area of higher concentration
to an area of lower concentration
FACILITATED DIFFUSION - molecules diffuse through a membrane with the help of proteins
OSMOSIS - the diffusion of water through a selectively permeable membrane
Hypertonic Solution | | Hypotonic Solution | | Isotonic Solution
ACTIVE TRANSPORT - molecules are moved against the concentration gradient. This requires the use of cellular energy, also usually involves a carrier molecule.
Exocytosis = transport of particles out of the cell | Endocytosis = transport of particles into the cell
Pinocytosis - liquids taken in, cell engulfs a droplet of water
Phagocytosis -solids taken in. a vesicle forms.
Where does the energy come from to power this type of transport?
A. Mitosis (nuclear
B. Cytoplasmic Division (cytokinesis)
C. Interphase (growth)
D. Differentiation - cells become specialized, developing characteristics in structure and function
INTERPHASE - growth of cell occurs, chromosomes are duplicated and other structures and organelles are produced
DIFFERENTIATION - occurs as cells multiply and organism develops and grows