Chapter 3 Cells Flashcards
Human cells have 3 basic parts:
Plasma membrane, cytoplasm, nucleus
The study of cells
Cytology
What kind of bilateral is the plasma membrane?
Phospholipid
Plasma membrane structure
Dynamic fluid structure, is selectively permeable, seperated intercellular fluid (ICF) from extracellular fluid (ECF)
Membrane lipids
75% phospholipids
5% glycolipids
20% cholesterol
Phospholipids parts
Polar Hydrophilic phosphate heads and unipolar hydrophilic fatty acid tails
Define Glycolipids
Lipids with sugar groups, cell identification
Membrane proteins
Integral and peripheral proteins
Integral protiens
Firmly inserted in membrane, mostly transmembrane protiens
Peripheral protiens
Loosely attached to integral protiens
Define glycocalyx
Fuzzy stick “sugar covering” at cell surface (glycolipids and glycoproteins
Acts as biological market allowing cells to recognize eachother
Cell junctions
Tight junctions
Desmosomes
Gap junctions
Tight junction
Impermeable junctions that prevent molecules from passing through intercellular space, in lining of intestines
Desmosomes
Anchoring junctions to prevent desperation of cells and withhold mechanical stress
Gap junction
Communication junction that allow small molecules to pass from cell to cell, cardiac muscle & smooth muscle
Passive transport
Does not use ATP
Diffusion
Movement of molecules down their concentration gradient
Different diffusions
Simple diffusion
Facilitied diffusion
Simple diffusion
diffusion of solutes through plasma membrane without using a channel or carrier
Speed of a molecule is determined by
Size and temp and concentration gradient
Carrier mediated
Sugars and amino acids are moved through membrane via protein carriers
Channel mediated
Ions and water are moved through membrane via protein channels
Osmosis
Diffusion of a solvent through selectively permeable membrane, water moves from a solution with a higher concentration to a solution with lower concentration
Osmolarity
Measure of total concentration of solute particles in a solution
Isotonic solution
Solution with same solute concentration as a cellular fluid
Hypertonic solution
Solution with higher solute concentration than cellular fluid
Hypertonic solution
Solution with lower solute concentration than cellular fluid
Cells lose water and shrink if exposed to a
Hypertonic solution
Cells gain water and swell if exposed to a
Hypotonic solution
Active processes
Uses ATP to move substances across membrane
Active transport
Both primary and secondary active transport uses solute pumps to move substances against a concentration gradient
Primary active transport
Energy used to transfer molecules is directly from ATP
Secondary active transport
Energy used to transport molecules is from energy stored in ionic gradients created by primary active transport
Vesicular transport
Uses membraneous sacs to transport particles, macromolecules, and fluids across the plasma membrane or within the cell
Endocytosis
Transport into the cell
Phagocytosis
Endocytosis in which large, solid materials are brought into the cell
Pinocytosis
Endocytosis in which a small volume of extra cellular fluid with dissolved solutes is taken into a cell
Receptor-mediated endocytosis
Endocytosis in which specific substances bind to receptor protiens and are ingested
Membraneous sacs in vesicular transport
Vesicles
Transcytosis
Transport into, across, then out of cell
Vesicular trafficking
Transport from one area in the cell to another
Exocytosis
Transport out of cell
What does RMP stand for
Resting membrane potential
Resting membrane potential
A condition in which the inside of the cell membrane is negatively charged compared to the positively charged outside
The RMP ranges from
-50 to -100 mV