Chapter 3 Flashcards
What is Cytology?
Study of Cellular Structure and Function
How many kinds of cells are there in the human body?
200
What is considered the nucleus’ largest organelle?
Cytoplasm
What are the parts of the Cytoplasm?
1) Cytoskeleton –> The Supportive Framework of fillaments and tubules
2) Organelles –> Diverse Structures performing tasks in the cell
3) Inclusions –> Accumulated cell products (e.g. lipids, pigaments and bacteria)
4) Cytosol –> Clear gel embedding the other components
Another name for the Cytosol is
Intracellular fluid (ICF)
The Extracellular Fluid (ECF) between the cells is referred to as ________?
Tissue Fluid
What is the Plasma Membrane?
1) Membrane at cell surface
2) Defines boundary of the cell
3) Governs interactions with other cells
4) Maintains chemical composition differences (between ECF and ICF)
5) 2 -layered lipid film with embedded proteins
What are Phospholipids?
Lipid in the Plasma Membrane which is highly fluid and is 75% of lipid molecules. They have Hydrophillic head (faces water on inside and outside of cell) and 2 Hydrophobic Fatty acid tails (Forms middle of Phospholipid bilayer away from water.
What is Cholesterol?
The lipid in the Plamsa Membrane which is 20% of lipid molecules. Affects membrane fluidity. If too much, inhibits proteins and molecules in membrane. If too little, Plasma Membrane Fragile.
What is the difference between Integral and peripheral proteins?
Inegral proteins penetrate the cell membrane and have glycoproteins (Proteins with carbohydrates attached). Peripheral proteins do not protrude into phospholipid; they are usually on intracellular face.
What are some functions of Membrane Proteins?
1) Receptors
2) Enzymes
3) Channel Proteins
4) Carriers
5) Cell identity markers
6) Cell Adhesion Molecules (CAM) –> Link cells to each other, link cells to extracellular material, bind tissues together, needed for sperm-egg binding, and immune cell binding
What is Glycocalyx?
- Fuzzy Carbohydrate coat covering cells
- Short sugar chain of glycolipids and glycoproteins.
- Function as cell-adhesion molectules, cushions plasma membrane, helps in ability to distinguish healthy cells, and determines human blood type and transfusion compatibility
What is Microvilli?
Extension of plasma membrane, serves primarily to increase surface area (Gives cell up to 40 times more surface area), well developed in taste buds and inner ear.
What are Cillia?
- Hair-like extensions
What are Motile Cilia?
- Less wide-spread
- Abundant in mucous membranes of respiratory tract (Moves mucus from lungs to throat)
- Abundant in Uterine Tubes (Move egg or embryo to uterus)
What are cell junctions?
Formed by proteins at cell surface, link cells together, attach them to extracellular material.
- Enable cells to grow/divide normally, resist stress, and communicate with each other
What are the 3 types of Cell Junctions?
1) Tight Junctions –> Completely encircles epithelial cell near upper end. Formed by fusion of fusion of plasma membrane of adjacent cells. Makes it difficult for substances to leak between cells (digestive juices from seeping between epithelial cells)
2) Desmosomes –> Hold cells together at specific point, not continuous, keep cells from pulling apart, enable tissues to resist mechanical stress, common in epidermis and cardiac muscle
3) gap junctions –> Formed by ring of proteins surrounding channel. Diffusion through channel
What are half desmosomes called?
hemidesmosomes –> anchor epithelial cell to basement membrane
What does it mean that the plasma membrane is selectively permeable?
- Allows some substatnces to pass
- Holds back others
- Multiple method of transport through cell’s surface
What is simple diffusion?
- Net movement of particles from high concentration to low concentration (i.e. down a concentration gradient)
- How O2 & Steroid Hormones enter a cell
- Does not require energy by cell
