Cell Review Flashcards
4 Components of cell theory
- Cell is the unit of organization in living things
- Building Block of organisms
- Cells come from previous cells
- All metabolic processes occur in cells
Three main parts of a cell
Cell membrane, cytoplasm (with organelles), nucleus
Plasma Membrane
Separates the intracellular fluid from the extracellular fluid, aka interstitial fluid
Fluid Mosaic Model
Lipid bilayer has membrane lipids, phospholipids.
Hydrophilic polar heads
Hydrophobic nonpolar tails, most unsaturated/kinked appearance
-Glycolipids: sugar groups
-Cholesterol: decreases mobility of membrane, increases stability
2 types of Membrane Proteins: Integral & Peripheral
Integral are firmly inserted in bilayer, protrude on both sides. Hydrophobic and hydrophilic regions
–Transport proteins (channels, carriers) enzymes, or receptors
Peripheral are not embedded in bilayer, loosely attached
–Enzymes, motor proteins for shape changes, cell to cell connections
Cytoplasm
Cytosol
Cytoplasmic organelles
Inclusions
- Material between plasma membrane and the nucleus
- Largely water with dissolved protein, salts, sugars, and other solutes
- Metabolic machinery of the cell
- Chemical substances such as glycosomes, glycogen, granules, and pigment.
Cell is like a Balloon filled with water
Hydrostatic properties, helps cell maintain shape
6 Functions of Membrane proteins-
Transport:
Spans the membrane, provides a channel across the membrane. Some need ATP to actively pump.
Receptors for signal transduction
Like an elevator button, signal causes a chain of chemical reactions.
Attachment to the cytoskeleton and extracellular matris
Helps maintain cell shape and fix the location. Stability and Strength.
Enzymatic Activity
Sequence of steps, metabolic processes.
Intercellular Joining
Hooks the membranes together. Lock and Key. Cell adhesion.
Cell-to-Cell Recognition
How cells recognize each other, identification tags.
Osmosis
Diffusion
- Movement of water
- Movement of molecules across membrane
Simple Diffusion
Facilitated Diffusion
Carriers
- diffuse directly through barrier
- pass through a carrier protein
- membrane proteins allowing specific molecules through
Sodium Potassium Pump
requires ATP, takes sodium out of the cell, potassium inside. Against concentration gradient
Exocytosis
Endocytosis
Phagocytosis
- Moves stuff out of the cell
- Moves stuff into the cell
- Engulfs solids and brings them inside
Tight Junctions
Like Rivets, close off space between cells, skin cells, continuous wall
Gap Junctions
In cytoplasm between cells, directly together, allows molecules to pass through pores (Connexons)
Desmosones
Create strong anchorage to tissue, Rivets or spot welds anchor cells together at plaques
Cytoplasm organelles
some have membranes, others do not. Organelles can be seen as small organs.
Mitochondria
Contains own DNA and RNA, powerhouse of cell, ATP for energy
Ribosomes
Site of protein synthesis, Free ribosomes and membrane-bound ribosomes
Endoplasmic Reticulum
Rough: studded with ribosomes to make secreted proteins
Smooth: synthesize phospholipids for cell membranes
