Anatomy Chapter 2 The Cell Flashcards
Cells are little factories which can do what 5 major things?
- Concentrate needed molecules
- Expel waste
- Synthesize large molecules with complex functions
- Generate, store, and use energy for metabolic processes
- Move
What does cytology mean?
The study of cells
Diseases begin at what level?
Cellular level
Cells are divided into what 2 categories?
Sex cells (sperm and egg/germ gametes), and Somatic cells (cells of the body)
The plasma membrane controls movement of molecules into and out of the cell, so it is therefore _________.
Selectively permeable
What are 5 purposes for the extracellular fluid?
Usually watery fluid, it is the matrix of connective tissue, little intercellular space in some tissues, provides medium for nutrients gas and waste, may be blood or lymph within specific vessels.
What are the 4 functions of the plasma membrane?
Physical isolation of cell contents from extracellular fluid, sensitivity to changes in extracellular fluid, structural support of the cell, regulation of exchange of materials between the cell and the extracellular fluid.
What are the 3 molecules of the plasma membrane and what percentage of the membrane do they make up?
Lipids (75-25%), Protein (25-75%), Carbohydrate (0-5%)
What are the two types of lipids within the plasma mebrane?
Phospholipid (most abundant), and cholesterol (tucked btwn phospholipid)
Why is cholesterol an important part of the plasma membrane?
Contributes to the membrane’s fluidity and stability, helps stabilize the phospholipid position, and decreases permeability of membrane to H2O
What do you call the unique design of the phospholipid molecule (hydrophilic head and hydrophobic tail)?
Amphipathic
What are the 6 protein functions?
- Water filled pathways, or channels
- Carrier molecules
- Membrane bound enzymes
- Receptor sites
- Cell adhesion molecules (CAMs)
- Proteins on surface are important in cells ability to recognize “self” and in cell-to-cell interaction
Glycolipids and glycoproteins “sugar coat” the cell. Why?
To help cells bind; useful for cell identification (like a fingerprint)
Name and describe the 4 passive processes
- Diffusion (substance is moved from higher concentration to lower concentration by way of kinetic energy)
- Facilitated diffusion (lipid-insoluble substances helped by membrane carrier proteins down a concentration gradient
- Osmosis (movement of water molecules across a membrane)
- Filtration (dissolved solutes moved across a membrane by external mechanical forces e.g. Gravity or hydrostatic blood pressure)
Name the 3 types of active processes
- Active transport (substances transported via membrane carrier protein usually against conc. gradient. ATP is used!)
- Exocytosis (substances transported via vesicle. It fuses to membrane and opens up to outside. Independent of conc. gradient.)
- Endocytosis (the cell membrane engulfs/wraps around a molecule. It forms a vesicle by pinching off and bringing the vesicle within. It is independent of conc. gradient.)
