Cells I
What are the two types of proteins that may be found in the plasma membrane?
- integral = extending through full thickness of plasma membrane; channels/pores, carriers, enzymes, hormone receptors
- peripheral = attached loosely; enzymes, holding cells together or helping them change shape
Describe the difference between passive and active transport.
- passive transport = no energy necessary
- active transport = energy necessary (ATP or GTP)
What is the biggest example of active transport in the body?
Na+ K+ pump/sodium-potassium pump
What are the 4 tissue types?
- epithelial
- connective
- muscle
- nervous
What are the common characteristics of connective tissue?
- primarily made up of non-living extracellular matrix
- all connective tissues form from mesenchyme
What is the role of cholesterol in the plasma membrane and what is the plasma membrane made of?
-stiffen the plasma membrane, providing stability
-phospholipid bilayer with hydrophilic head and hydrophobic tail
What 3 factors affect the rate of diffusion?
- concentration = higher concentration means faster diffusion
- molecular size = smaller molecules means easier diffusion
- temperature = higher temperature means faster diffusion
When would active transport be appropriate?
- solute is too big to get through plasma membrane and its channels
- move solute against its concentration gradient
- solute not lipid soluble and therefore is unable to pass through the plasma membrane
What 6 functions do epithelial tissue serve?
- protection
- absorption
- filtration
- excretion
- secretion
- sensory reception
What are the 3 types of muscle tissue?
- cardiac muscle
- skeletal muscle
- smooth muscle
Name the 3 types of cell junctions, describe them, and give an example of each.
- tight junctions = impermeable; epithelial cells in digestive tract, blood-brain barrier, etc.
- desmosomes = velcro junctions to prevent sheering force; heart muscle, skin, etc.
- gap junctions = communicating junctions; electrically excitable tissues: heart, nerves, smooth muscle, etc.
Name the two types of active transport processes.
- active transport = energy necessary to move molecules for a number of reasons
- vesicular transport = fluids with large particles are moved across plasma membrane in a membranous sac (vesicle)
What are the 4 types of vesicular transport?
- endocytosis = moving stuff into the cell
- exocytosis = moving stuff out of the cell
- transcytosis = moving stuff into, across, then out of cell
- vesicular trafficking = moving stuff around within the cell
Describe how epithelial tissues are classified.
- by shape at the apical surface: squamous, cuboidal, and columnar
- by layers: simple or stratified
- pseudostratified looks multilayered but the cells are just all different heights
What are the structural components of connective tissue?
- ground substance: interstitial fluid, cell adhesion proteins, GAGs
- fibers: collagen, elastin, reticular
- connective tissue cells: resident cell type in each type of connective tissue
Lipids and proteins may be found on carbohydrate regions of plasma membranes, what purpose do they serve and why is that important?
- glyoproteins and glycolipids serve to identify cells as self cells, meaning they belong to the body and aren't foreign
- this ability to distinguish self cells and non-self cells are what allow our immune system to do its job
Name and describe the 3 passive transport processes.
- simple diffusion = molecules moving from areas of high concentration to low concentration (down concentration gradient)
- facilitated diffusion = substances move down their concentration gradient using a carrier molecule or transport protein
- osmosis = solvents move through selectively permeable membrane when water concentration differs on either side
Name and describe the 3 types of endocytosis.
- phagocytosis = macrophages or phagocytes engulfing bacteria
- pinocytosis = small sips of fluid with dissolved solutes
- receptor-mediated endocytosis = receptors let in only specific substances they are designed to accept
Name at least 3 types of connective tissue cells and explain the difference between "-blasts" and "-cytes".
- chondroblasts/chondrocytes
- fibroblasts/fibrocytes
- osteoblasts/osteocytes
- adipocytes
- WBCs/leukocytes
- mast cells
- macrophages
Cartilage is avascular and non-enervated, what does this mean for the patient and why do they experience pain when it is injured?
- cartilage itself sustaining damage is not felt however, what does cause pain is the underlying bone rubbing with another
Name at least 2-3 functions of proteins in the plasma membrane.
- receptor for hormones and other chemical messengers
- enzyme to break down chemicals and end a response/reaction
- channel to continually allow substances through the plasma membrane
- gated channel to allow substances to move through plasma membrane at certain times
- cell identity marker to distinguish self cells from foreign cells
- cell adhesion molecule to join together two cells
What is tonicity and what are the 3 categories of tonic solutions and their tonicity?
- tonicity = ability of solution to change cell's shape based on cell's internal water content
- hypotonic = containing less solute than in the cell; cause cell to swell
- hypertonic = containing more solute than in the cell; causes cell to shrink/shrivel
- isotonic = containing same solute as the cell; causes no change in cell
Explain or draw how the sodium-potassium pump works.
- Potassium leaks out of the cell through plasma membrane channels
- in the presence of potassium, sodium moves into the cell through plasma membrane channels
- the sodium potassium pump then activates, bringing potassium back into the cell and kicking sodium out of the cell
Name the 4 primary types of connective tissues and any major subtypes.
- connective tissue proper: loose CT and dense CT
- cartilage: elastic, fibrocartilage, hyaline cartilage
- bone tissue: compact, spongy
- blood
What are the 3 stages of tissue repair?
- inflammation
- granulation tissue
- regeneration & fibrosis