Exam 1 Flashcards
Where is most of the total body water, and what percent resides there?
67%, intracellular or within the cytoplasm
Where is the majority of the extracellular body water?
Tissue fluid, or interstitial fluid (80%)
Where is 20% of the extracellular body water contained?
blood plasma
What is excess fluid in the part of the body that contains 80% of the extracellular body water called?
edema
What mediates exchange of molecules between blood and cells?
the interstitial fluid
What is the extracellular matrix composed of?
elastin and collagen, ground substance
What is the gel-like material of the ECM composed of?
glycoproteins, and proteoglycans (or mucopolysaccharides)
What provides the structural strengths to connective tissues?
collagen and elastin (iron bars)
What is one type of protein that contribues the the basal lamina of epithelial membranes?
Collagen IV
How does the basal lamina wed the epithelium to underlying connective tissues?
Forms chemical bonds between carbohydrates from the outside of the PM of epithelial cells and the glycoproteins/proteoglycans of the ECM in connective tissues
What is the glue between cells and the ECM and how does it work?
integrins (glycoprotein), extends form cytoskeleton through the PM and into the ECM
What 2 diseases are exacerbated by an enzyme that requires zinc ion cofactor and what is the protein called?
Cancer and arthritis, matrix metaloproteinases (MMP)
What types of molecules pass easily through a phospholipid bilayer?
nonpolar
What is the difference between channels and carriers?
Channels open or close, carriers change configuration
What are 2 types of carrier mediated transport?
Facilitated diffusion, active transport
What are 3 types of non carrier mediated transport and what do they pass through?
Simple diffusion- lipid soluble
Simple diffusion of ios- membrane channels
Simple diffusion of water- aquaporin channels
What kind of processes are included in passive transport?
All non carrier mediated transport and facilitated diffusion
What kind of transport uses pumps and which direction does it move on the concentration gradient?
active transport, against
What powers active transport?
ATP
What is the driving force of diffusion?
Brownian motion
What is the difference between diffusion and net diffusion?
Net diffusion involves the net movement until the concentration difference no longer exists, diffusion is just mostion
How are microwaves related to diffusion?
They speed up the molecular motion of water to generate heat
Why can O2 molecules or steroid molecules pass easily through a phospholipid bilayer?
They are non polar/ lipid soluble
Plasma membranes regulate the movement of what part(s) of a solution?
solutes and solvents
How does the oxygen concentration compare inside and outside of the cell and how does this concentration effect its movement?
Low inside, high outside, wants to move inside
How does gas exchange occur?
diffusion between cells and their extracellular environment
T/F water can diffuse without aquaporins? Why/why not?
True because they are small and lack a net charge, but it is limited
Osmosis is the simple diffusion of what?
a solvent (water)
What kind of molecules require carrier proteins for transport?
Large, polar (like glucose)
T/F: carrier proteins always require energy?
False
What are two kinds of specific channels that open/close in response to changes in membrane voltage?
NA+ and K+
What two types of body cells are excitable?
Muscle and nerves
What procedure channels blood through an external filter to separate wastes?
hemodialysis
What serves as the semipermeable membrane in peritoneal dialysis?
your own peritoneal membrane
What glycoprotein is abnormal in cystic fibrosis?
cystic fibrosis transmembrane conductance regulator (CFTR)
Where are epithelial membranes found?
sweat glands, pancreatic ducts, small respiratory airways
What 4 things influence the rate of diffusion?
MAGNITUDE of concentration difference, permeability of the membrane, temperature of the solution, surface area of the membrane
What serves as the driving force for diffusion?
random motion of water, the magnitude of concentration difference
In a resting neuron, the PM is more permeable to K+ or Na+? Which diffuses quicker?
K+
A crushing impact to the skull could release a fatal amount of what into the body?
potassium
Why does increased temperature speed up diffusion?
because it proportionally increases the random movement of water, which increases the movement of solute molecules
How is the surface area of membranes increased?
numerous folds
What aids the rapid passage of digestion products across the epithelial membranes in the small intestine?
microvilli, tiny finger like projections
What are the requirements of osmosis
requires water and a selectively permeable membrane
When are solutes considered osmotically active?
When they cannot freely pass through the membrane
What is the pressure needed to just stop osmosis?
osmotic pressure
Why do animal cells lyse in pure water?
they lack cell walls
What is the osmotic pressure of pure water?
zero
Why is water drawn in from interstitial fluid to capillary blood?
because concentration of plasma proteins is higher in capillaries and capillary blood is osmotically active
What can a low concentration of plasma proteins lead to?
edema
Why does a damaged liver lead to edema?
it is unable to produce albumin, which is a major plasma protein, thus there is a low concentration of protein in blood and water accumulates in the interstitial fluid
What is osmotic pressure generated by?
the solute
What are 3 common signs of diabetes?
hyperglycemia, polyuria, excessive thirst
What is avogadro’s number?
the number of molecules in a mole 6.02X10^23
What is one molar solution?
1 mole of solute dissolved in water to make 1 liter of solution
Why is more water needed to make 1.0M of NaCL than 1.0M glucose?
because a mole of NACl is 58.5 grams and a mole of glucose is 180grams, which takes up more volume
Why is molality better used to measure osmosis?
because the ratio of solute to water molecules is important
What is osmotic pressure dependent on?
the ratio of solute to solvent
What is the expression for the total molality of a solution?
osmolality (Osm)
What is the osmolality of 1.0 m of NaCl?
2 Osm
What method is used to determine osmolality?
freezing point depression
What is the freezing point of a solution based on?
the total concentration of solution
Why does adding salt to ice melt it?
because it changes the concentration of the solute and thus, the freezing point
What is the osmolality of human plasma?
300 mOsm
What does 5% detrose indicate?
5 grams of glucose per 100ml
How many grams of glucose are in an isosmotic solution of 1 L of water?
50 grams
How many grams of NaCl per 100ml are in an isosmotic solution to human plasma?
.85grams
if a isosmotic gluce or saline solution was separated from plasma by a membrane that is permeable to water but not to glucose or NaCl, will osmosis occur? What is this solution called?
No, isotonic
What cells are shaped like biconcave discs? Why?
RBCs, lose their nucleus
Why is saline better to clean wounds than tap water?
It is isotonic
Why does hemolysis occur when RBCs are placed in water?
hypotonic solution
What does tonicity refer to?
the effect of solution on the the osmotic movement of water
What happens when RBCs are placed in seawater?
crenation
When would you use mannitol intravenously?
cerebral edema
What intravenous solution contains ions that resemble electrolytes in plasma?
Ringer’s lactate
Where are osmoreceptors generally located?
the hypothalamus
What happens during dehydration?
water leaves osmoreceptors because of increased osmolality of extracellular fluid, osmoreceptors shrink, which mechanically stimulates increased production of nerve impulses, person increasees water intake and excretes less urine
What happens when a person is dehydrated and the body excretes less urine?
osmoreceptors in hypothalamus stimulate the posterior pituitary which releases ADH (vasopressin)–> acts on the kidneys to promote water retention
Where is ADH manfactured
hypothalamus
How does eating a lot of salt affect the blood?
increases blood volume and blood pressure
Why does the blood volume increase when eating salty food?
because ADH is released and so they excrete less urine and also drink more until the salt is diluted, which increases blood volume/pressure
Hyponatremia leads to what?
More water excretion, low blood volume and blood pressure, can be fatal
Why are genes considered by some to be “selfish”?
because it is thought that an organism exists so that genes can survive beyond mortal life
What is the purpose of genetic diversity?
it ensures some members of the population with survive environmental changes
What is reduction division?
meiosis
How many chromosomes does each gamete have?
23
What is the fusion of a sperm and ovum?
fertilization
How many chromosomes are in a fused sperm and egg?
46
How does a zygote grow into an adult?
mitosis
T/F: a zygote has 46 different chromosomes
False, 23 homologous pairs
What are the first 22 pairs of chromosomes called
autosomal chromosomes
How many alleles of each gene are on autosomal chromosomes? How many alleles are usually expressed?
2 sets, both
How is an allele silenced?
epignetic changes to the chromatin, methylation of cytosine bases in DNA and acetylation of histone proteins in chromatin
What is the term that describes epigenetic changes in the zygote that silences an allele from one parent and expressing the nonimprinted allele of another parent in the offspring?
genomic imprinting
what recombines with the y chromosome during meiosis?
the tip of the x chromosome
what is a region of DNA bases that can be read from either direction?
palindrome
Where are testis specific genes located??
y chromosomes
Why can testis specific genes correct defects within themselves?
gene conversions, they are located in palindromes
Why is sex determination completely random 50/50 chance?
because half the sperm cells produced will contain an x and half will contain a y
Each diploid cell in a woman inherits ___ x chromosomes and ____ is activated
2, 1
how are x chromosome inactivation and genomic imprinting related?
They both result in expression of only one allele of a pair
What determines the sex of a child?
the sperm
If you saw a Barr body in a cheek cell, what would you know?
the cell came from a woman
What is the clump of heterochromatin seen in cheek cells formed from?
the inactive x chromosome
If you saw a drumstick appendage in a nucleus, what kind of cell would it be and what gender would the owner of the cell be?
neutrophil, female
If you took a ultrasound 4 weeks into a pregnancy, could you determine the gender of the fetus?
no, females and males look the same for about 40 days into development
What cells produce sperm? ova?
spermatogonia, oogonia
What is the default setting of an embryo?
female
What substance is necessary for testes to form?
testis determining factor (TDF)
Where is the gene for TDF located?
the short arm of Y chromosome
What characteristics are shared by enzymes and proteins?
specificity, competition, saturation
What happens to the rate of transport when 2 molecules are competing for the same carrier?
it is lower
What measurement indicates saturation?
transport maximum (Tm)
What disease results from inadequate secretion of inaction of insulin?
diabetes mellitus
What element of proteins and enzymes accounts for glycosuria?
saturation (of carriers)
How is glucose transported from blood across plasma membranes?
facilitated diffusion
What are two words that describe carrier proteins that do the same job?
isoforms, isomeres, isoenzymes
Where does GLUT 4 exist and what regulates its existence?
muscles and adipose tissue, insulin and exercise
What common cellular process is similar to the way GLUT 4 fuses with the PM?
exocytosis
T/F: glucose is always transported down its concentration gradient. Why/why not?
False, in certain places (epithelial cells of tubules and small intestine) it is transported against and uses a different carrier that simiultaneously transports Na+
T/F: fatty acids are transported across the PM by simple diffusion. Why/why not?
false, fatty acid transport carriers facilitate diffusion out of adipocytes and into blood/organs
What can occur if one overdoses on insulin?
hypoglycemia: LOC or death
What happens when a cell is poisoned with ATP?
inhibits oxidative phosphorylation (no atp)
What are 3 ATPase enzymes?
Ca2+, H+, Na+/K+
The Ca2+ pump removes Ca2+ from the ______ and pumps it into the _________
cytoplasm, endoplamic reticulum
What happens when ion channels are opened for Ca2+?
it diffuses rapidly into the cytoplasm
What does the sudden rise of cytoplasmic ca2+ do?
signals a diverse amount of processes, like releasing neurotransmitters
What does much of the body’s energy go to?
maintaing Ca2+ pumps
What goes out and what comes in the sodium potassium pump?
3 Na+ out 2 K+ in
Where is Na+ more highly concentrated?
The extracellular fluid
What provides the electrochemical impulses needed for nerve and muscle cells?
Na+/K+ pump
Why is extrusion of sodium important for osmotic reason?
if Na+ concentration is increased in cytoplasm, it promotes osmotic inflow of water which damages cells
What molecules is important for coupled transport?
Na+
What condition correlates with a large U wave?
hypokalemia
what disease is associated with muscle weakness and low potassium?
hypokalemic periodic paralysis
What channel is affected in hypokalemic periodic paralysis?
voltage gated calcium channels (R1RY type)
Why is calcium conductance important?
need to reach threshold so muscles can contract
Why is hypokalemic periodic paralysis often misdiagnosed and what is it diagnosed as?
conversion or hysterical paralysis disorder, because it doesn’t correspond with any nerve or spinal root distributions and is exacerbated when epinephrine is released in fight or flight situations
What is the most important energy source for the brain?
glucose
In secondary active transport, the ____ movement of a molecule or ion is obtained from the _____ movement of transport of ____ into the cell
uphill, downhill, Na+
If a molecule/ion is moved in the same direction as Na+ the it is _____ or ______
cotransport, symport
If the molecule moves in the opposite direction as Na+ then the process is called _______ or ________
countertransport or antiport
Where is ATP used in the Na+Ca2+ exchanger?
maintaining the steep concentration gradient of Na+
The Na+Ca2+ exchanger is an example of what kind of transport?
countertransport
What drug induces stronger contraction of the heart in CHF and how does it happen?
digitalis, inactivates the Na+/K+ pump which reduces activity of Na+Ca2+ exchanger (increased intracellular sodium reverses the exchanger so more Na+ leaves the cell and more Ca2+ enters, strengthening contractions)
Would poisoning a cell influence secondary active transport?
Yes
The concentration gradient for Na+ means that intracellular Na+ is ______
high
What process removes molucules taht are too large to be transported by carriers? Ex of molecules
exocytosis, hormones or neurotransmitters
How is cholesterol removed from the blood by the liver and the walls of blood vessels? What common condition is this related
receptor mediated endocytosis, artherosclerosis
What are the 2 forms of bulk transport?
exocytosis and endocytosis
