CH 3 Flashcards
Cell Theory(Cells)
-All living things have at least one cell
-The cell is the smallest unity in the characteristics of life
-All cells come from pre-existing cells
Two major classifications
Prokaryotic cells-bacteria
Eukaryotic cells-plants, animals, fungi, protists
Cell classification: Prokaryotic Cells
Plasma membrane
Cytoplasm: fluid within membrane
Lack a nucleus
Lack membrane-bound organelles
Cell classification: Eukaryotic Cells
Plasma membrane
Cytoplasm: fluid within membrane
Nucleus: membrane bound
Organelles: membrane bound structures with specialized functions
Why are cells small?
To stay efficient
3 types of microscopes
Light Microscope (LM)
Magnifies up to 1000X
Transmission Electron microscope (TEM)
Magnifies up to 100,000X
Scanning Electron Microscope (SEM)
Magnifies up to 100,000X AND provides a 3-D view of cell surface
Separates the cell from its environment
Plasma Membrane
Plasma membrane contains __, __, and ___
lipid bilayer, cholesterol, and various proteins
How do Molecules cross the plasma membrane?
-active transport
-passive transport
-Endocytosis or exocytosis:
Moving materials into and out of cell
types of passive transport
-small, lipid soluble: molecules that move directly through the lipid bilayer
-some water-soluble: molecules can cross the plasma membrane by using protein channels
-Osmosis: diffusion of water
-Facilitated diffusion: through a transporter protein in the membrane
Active transport - moves a substance from an area of ___ concentration to an area of ___ concentration:
Lower;Higher
Types of active transport
Bulk Transport:
Used to move larger molecules across the membrane
Endocytosis - brings substances into the cell
(using a vesicle)
Exocytosis - expels substances from the cell
(using a vesicle)
-Composed of RNA and proteins
- makes specific proteins
Ribosomes
-Synthesizes most of the chemical compounds that are made by the cell
-connected to the nuclear membrane
Endoplasmic Reticulum (ER)
Difference between rough er and smooth er
Rough ER:
Has ribosomes on surface
Smooth ER:
Lacks ribosomes on surface
