Cell Biology & Genetics Flashcards
What does the endoplasmic reticulum do?
Rough ER processes proteins. Smooth ER processes lipids.
What are the functions of the cell membrane?
Protection, transport nutrients/wastes, generate action potentials, growth regulation
3 factors that affect the net rate of diffusion?
- concentration difference
- electrical potential
- hydrostatic pressure
What is osmosis?
Movement of water to achieve homeostasis - always moves DOWN it’s concentration gradient
How do lipid soluble molecules move across the cell membrane?
simple diffusion
How do water soluble molecules move across the cell membrane?
Assisted by transporter proteins
What are the two types of protein transport across a cell membrane?
- Passive - diffusion
2. Active - using energy
What is diffusion?
Movement of solutes down a concentration gradient, does not use energy
What is active transport?
Moves against a concentration gradient, requires energy.
What can stimulate the opening of ion channels?
- change in membrane potential
- Ligand signal
- Change in shape of cell
What are the different types of intercellular signaling?
- Gap Junctions
- Direct cell-to-cell
- Ligand Signal
What are the examples of ligand signaling?
Synaptic, Paracrine, Endocrine, Autocrine
What is paracrine ligand cellular signaling?
Signaling across the extracellular space
What is endocrine signaling?
Hormonal signaling via the bloodstream
What is autocrine signaling?
Cells auto regulation, feedback signaling to itself
What is hydropic swelling?
Reversible cell injury, results from failure of Na/K pump
What is hypertrophy of cells?
Increased size
What is hyperplasia?
Increased number of cells
What is metaplasia?
Change in cell type
What is dysplasia?
Disorderly growth (leads to cancer)
What is coagulative necrosis?
f/ ischemia, most common.
What is liquefactive necrosis?
Lysis of lysosomes, forms abccess or cyst.
What is fat necrosis?
Death of adipose tissue, appears white, from trauma or pancreatitis
What is caseous necrosis?
Lung damage f/ TB, resembles cheese
What is dry gangrene?
From coagulative necrosis; black/dry tissue, clear lines of demarcation
What is wet gangrene?
From liquefactive necrosis, in internal organs
What is gas gangrene?
from anaerobic bacteria, results in gas bubbles
What are the 3 ways apoptosis is triggered?
- Withdrawal of survival signals
- Fas Ligands
- Internal (p53)
What is Senescence?
Self realized end of cellular life, related to length of telomeres.
What are the two types of genetic mutations?
- Point mutation - single base pair
2. Frame shift mutation - creates abnormal proteins
What are autosomal disorders?
Affect the # or shape of chromosomes
What are the 3 sex chromosome disorders?
- Klinefelter’s
- Turner’s
- Multiple x or y
In autosomal dominant disorders, what are the chances that 1 normal and 1 affected pass it along? And 2 affected parents?
1 normal parent, 1 affected parent = 50% chance
2 affected parents = 75% chance
What are examples of autosomal dominant disorders?
Marfan’s, Huntington’s, familial HLD, neurofibromatosis
In autosomal recessive disorders, what are that chances that two carriers pass it along? 1 affected and 1 carrier?
2 carriers = 25% chance
1 affected, 1 carrier = 50% chance
What are examples of autosomal recessive disorders?
Albinism, CF, Sickle cell
What are the chances that an affected father passes along a sex linked disorder to his daughter?
All of his daughters will be carriers.
If a mother is a carrier of a sex linked disorder, what are the chances she will pass it along?
50% of affected son or carrier daughter.
What are examples of sex linked genetic disorders?
Hemophilia A/B, Duchenne, DI
What is epigenetics?
A change in the phenotype (trait expressed) without a change in the genotype (genetic code).
What is the difference between DNA sequence mutations and epigenetic modifications?
Epigenetic modifications potentially can be reversed
In addition to osmosis, what force is involved in the movement of water between the plasma and interstitial fluid spaces?
Hydrostatic pressure
A major determinant of the resting membrane potential necessary for the transmission of nerve impulses is the ratio between what?
Intracellular K+ and extracellular Na+
What does the loss of the adenosine triphosphate (ATP) during ischemia cause cells to do?
Swell because of the influx of sodium chloride (NaCl)
