MCAT Q&A -Summer 2011 Flashcards
what’s the opposite of a vector quantity?
Scalar
energy is a [scalar/vector/neither] quantity.
Scalar
displacement is a [scalar/vector/neither] quantity
vector
time is a a [scalar/vector/neither] quantity
scalar
cos2θ + sin2θ = ???
1
what is mass percent? Define it.
(BR chem. 17)
mass of solute / mass of solution
what does ‘solvate’ (verb) mean?
Solvate (noun) is an aggregate that consists of a solute ion or molecule with one or more solvent molecules;
also : a substance (as a hydrate) containing such ions (m-w.com)
What is a lipid?
Any biological molecule that has low solubility in water (hydrophobic), and high solubility in nonpolar organic solvents.
what does amphipathic mean?
Polar at one end (hydrophilic),
nonpolar at the other end (lipophilic)
What are the six major groups of lipids?
Fatty acids;
glycolipids;
phospholipids;
steroids;
terpenes
triglycerides (EK Bio 2)
Fatty acids; triglycerides; phospholipids; glycolipids; steroids; terpenes (EK Bio 2)
what must be noted about the above list of 6 lipids?
triglycerides; phospholipids; glycolipids
are sometimes simply referred to as ‘fatty acids’ b/c fatty acids are a component of all of them
(EK Bio 2)
the main constituent of veggie oil and animal fat is ____
triglyceride
what are fatty acids?
i.e., describe their chemical components
they’re long chains of carbons truncated at one end by carboxylic acid
(EK BIO 2)
In humans, what is the max # of carbons for a fatty acid chain?
24
Are all fatty acids saturated?
No. fatty acids can be saturated or unsaturated
[saturated/unsaturated] fatty acids contain all single bonds
saturated
triglycerides are also called ____
triacylglycerols
what are the components that make up a triglyceride?
3 fatty acids bonded to a glycerol; according to Audio Osmosis it’s “3 carbon chains dangling from a 3-carbon backbone”
what is glycerol?
propan-1,2,3-triol
3 hydroxyl groups attached to 3 carbons
A 3-carbon backbone of triglycerides
What is the purpose of triglycerides?
To store energy, & provide thermal insulation and padding
special cells, AKA fat cells, whose cytoplasm contains almost nothing but triglycerides, are called _____
adipocytes
What are phospholipids?
A glycerol backbone with 2 fatty acids and a phosphate group attached
in what part of the cell do we phospholipids?
Cell membranes
where are glycolipids found abundantly?
In the membranes of myelinated cells of nervous system
what are steroids?
4-ringed structures
what is the major purpose/function of steroids?
To regulate metabolic activities
what are eicosanoids?
20-carbon-length fatty acids
what is the purpose/function of eicosanoids?
Local hormones
give examples of steroids.
Some hormones,
vitamin D,
cholesterol
what are terpenes?
Class of lipids
example of terpenes includes _______
vitamin A
In bio, what does the word “essential” mean?
Means cannot be produced by the body, so it must be ingested
how many, if any, of the 20 most common amino acids are ‘essential’?
between 8 to 11
What’s the ‘primary structure’ of a polypeptide?
The sequence and number of amino acids that form the polypeptide chain
what’s the ‘secondary structure’ of a polypeptide?
alpha-helix, or beta-pleated sheet
why does the helix, or the pleated sheet, form?
Forms from H-bonding
What does the suffux –PHAGE refer to?
Cells that “eat” (e.g., Macrophages)
The suffix can also refer to viruses.
What atoms/molecules specifically H-bonds in the secondary structures?
H-bonding between the carboxyl oxygen of one amino acid, and the hydrogen on the amino group (–NH2) of the other amino acid
True/False – 2nd-ary structures are created by interactions between the side chains of adjacent amino acids
False.
Created by interaction between atoms of the peptides’ backbone
What’s the tertiary structure?
Overall 3-dimensional structure of a single polypeptide chain
how is the tertiary structure created?
By variety of interactions among R-groups, or
between the R-groups and the peptide backbone
What types of chemical bonds make tertiary structures possible?
Disulfide bonds,
H-bonds,
ionic interactions between acidic and hydrophobic side chains;
van der Waals
What’s the quaternary structure of proteins?
Two or more polypeptide chains binding together
two broad types/categories of proteins are ____ and ____
globular and structural
What’s the difference between globular and structural proteins?
Structural proteins made from long polymers; they add strength to cellular and matrix structures
When you see nitrogen on the MCAT, think [nucleic acids/ some lipids / some carbs / proteins]
all of the above have nitrogen, but for the MCAT think PROTEIN
(EK Bio 6)
glucose is a #-carbon sugar
6
if glucose needs to be stored, it is converted by the body to _____
glycogen, or into fat
what is glycogen. Describe it.
Branched glucose polymer
Does glycogen have alpha or beta linkages?
alpha linkages
glycogen is stored mainly in ______?
stored in mainly the liver and muscles as glycogen. (wiki article on glucose)
The polysaccharides formed from glucose by plants are _______.
starch and cellulose
Given:
glycogen, cellulose, and starch.
Which of these have alpha linkages, which beta?
Glycogen and starch have alpha
the basic monomer of a DNA strand is ____
a nucleotide
Name the 3 components of nucleotides.
a 5-carbon sugar,
nitrogenous base,
phosphate group
what specific bond joins together individual nucleotides?
The phosphodiester bond
what bonding joins together the two strands of a DNA molecule?
The ‘rungs’ of the DNA spiral ‘ladder’ are held together by hydrogen bonding
(EK bio 8)
name the nucleotides that make up DNA
adenine,
thymine,
cytosine, and
guanine
how is RNA different from the above list of nucleotides?
RNA lacks thymine; instead has uracil
List other very important nucleotides, besides A T C G and U.
ATP;
GMP
cyclic AMP;
NADH; &
FADH2
What are ‘minerals’ when talking about them in biology?
The dissolved inorganic ions inside and outside the cell
[true/false] :
Enzymes alter the equilibrium of a rxn
false.
Enzymes are catalysts. Like any catalyst, enzymes don’t alter eq of a rxn
The reactant or reactants upon which the enzyme works, is called a _____
substrate
the part of the enzyme to which the substrate binds, is called _____
the active site
(EK bio 11)
Besides the lock-and-key model, there’s also the _______ theory/model
induced fit
explain ‘saturation kinetics’
as the concentration of substrate increases, the rate of rxn also increases, but
it’s diminishing returns until a Vmax is reached (horizontal asymptote)
What are coenzymes?
Organic molecule that serves as a type of cofactor
what are cofactors?
A non-protein component that many enzymes require to reach optimal activity
are vitamins related to coenzymes? If so, how?
Many vitamins or vitamin-derivatives are coenzymes
list the mechanisms by which enzyme activity can be blocked.
Competitive inhibition;
noncompetitive inhibition; and
irreversible inhibition
Competitive inhibition;
noncompetitive inhibition; and
irreversible inhibition
Which of the above 3 mechanisms is highly toxic?
irreversible
How do irreversible inhibitors work?
They bind covalently to enzymes (a few bond noncovalently)
describe non-competitive inhibition
the inhibitor bonds to an enzyme at a spot OTHER than the active site, and changes the conformation of the enzyme
The inactive form of an enzyme is called a/n?
zymogen, or
proenzyme
The shutdown mechanism for enzyme activity is called ____
negative feedback
Metabolism consists of ____bolism and ___bolism
catabolism,
anabolism
which –bolism means “building up”?
anabolism is molecular synthesis
The first stage of aerobic respiration is ___
glycolysis
The first stage of anaerobic respiration is____
glycolysis
briefly summarize/explain/define glycolysis
the series of rxns that break glucose molecule into two 3-carbon molecules of pyruvate
is pyruvate related to pyruvic acid?
yes
how is pyruvate related to pyruvic acid?
Pyruvate is the conjugate base of pyruvic acid
glycolysis produces a net of ____ ATP molecules
2
true/false:
glycolysis will not occur w/o oxygen
false.
It can occur with and w/o oxygen
anaerobic respiration is also called?
fermentation
in fermentation, pyruvate is turned into _____ in human muscle cells
lactic acid
yeast turns pyruvate into ____ during fermentation
ethanol
after glycolysis, what happens next with Aerobic respiration?
Pyruvate and NADH move into mitochondrion, where the pyruvate is converted into acetyl CoA
What’s the next step after pyruvate is converted to Acetyl CoA?
Krebs cycle
Krebs cycle is aka?
Citric acid cycle
and
Tricarboxylic acid cycle (TCA)
1 glucose molecule produces ___ turns of the Krebs cycle
2
Each turn of the Krebs cycle produces ___ ATP, ____ NADH, & ___ FADH2.
1 ATP,
3 NADH, &
1 FADH2
AERObic respiration, including glycolysis, produces a net ____ ATP molecules
36
- What is the electron transport chain?
- Where is it located?
Series of proteins called cytochromes in the inner membrane of the mitochondrion
In MCAT’s Newtonian physics, the two types of friction are:
static friction and kinetic friction
which of the two types of Newtonian friction is usually larger?
Static
What’s the temp of the human body, in Celsius?
37
What’s the molar mass of water?
18 grams per mole
What are the 4 broad groups for the 20 amino acids?
Nonpolar; polar; acidic, and basic
How do you remember the** basic** amino acids? [mnemonic device]
The basic acids with basic R groups are H-A-L
How do you remember the acidic amino acids?
They’re aspartic acid; and glutamic acid.
Just memorize them.
what chemical is the intermediate between pyruvate and the Krebs cycle?
Acetyl CoA
What does the electron transport chain really do? What is its purpose/function?
Pass down electrons from 1 protein to next. They pump protons into the inter-membrane space so that the inter-membrane space will have low pH.
What’s ATP synthase?
Integral protein of the inner membrane of Mitochondria
What does ATP synthase do?
allows protons to flow thru the membrane back into mitochondrial matrix;
The overall reaction sequence is:
ATP synthase + ADP + Pi → ATP Synthase + ATP
How does the body break down fat for energy?
[answer has several steps]
Triglycerides broken into glycerol and fatty acids;
glycerol enters glycolysis.
Fatty acids taken to mitochondrial matrix and turned into Acetyl CoA
How does the body break down proteins for energy? Specifically, where in the energy cycle do the proteins enter?
amino acids enter the production processes at different points, depending on the type of amino acid involved
where in the body is pyruvate converted to Acetyl CoA?
Inside the mitochondrial matrix
In aerobic organisms, when/why would fermentation occur?
If O2 were not present
Describe the fermentation process.
NADH oxidized back to NAD+;
(this process produces CO2 and ethanol (in yeast), or lactic acid in other organisms.)
What are the net products of glycolysis?
the net products of glycolysis:
2 atp; 2 nadh; 2 pyruvates
What’s substrate level phosphorylation?
Refers to the process of ATP production in the Krebs cycle
What’s oxidative phosphorylation?
The production of ATP using ATP synthase
What is helicase?
A motor protein
What does helicase do?
They move directionally along a nucleic acid phosphodiester backbone, separating two annealed nucleic acid strands by breaking the H-bonds between annealed nucleotide bases
What powers helicase?
the energy from ATP hydrolysis
True/False:
Helicase is just one protein that’s the same, no matter which organism it’s found in.
False.
There are many helicases (14 confirmed in E. coli, 24 in human cells) resulting from the great variety of processes in which strand separation must be catalyzed
How does helicase “move”?
move incrementally along one nucleic acid strand of the duplex with a directionality and processivity specific to each particular enzyme.
What’s the replication fork?
Structure that forms during DNA replication when the double helix unwinds and is partially unzipped
What is the function of DNA polymerase?
Adds nucleotides to a new strand of DNA
Can DNA polymerases start a new strand of DNA?
No.
They can only add new nucleotides to an existing strand of DNA.
DNA Polymerases can only add new nucleotides to an existing strand of DNA.
So then, what can start a new DNA strand?
a primer
What is a primer?
What is it made of, and
what is its function?
A primer is a strand of nucleic acid (most of the time it’s RNA) that serves as a starting point for DNA synthesis.
They are required for DNA replication because the enzymes that catalyze this process, DNA polymerases, can only add new nucleotides to an existing strand of DNA.
Where on the DNA strand does the polymerase start its replication?
The polymerase starts replication at the 3’-end of the primer, and copies the opposite strand.
what’s meant by the “fluid mosaic model”?
means that the phospholipids that make up the bilayer of a membrane can float around, but can’t separate from the bilayer
in eukaryotic molecules, ________ regulates membrane fluidity
cholesterol
What’s a lagging strand?
The lagging strand is that strand of the DNA double helix that is orientated in a 5’ to 3’ manner
All DNA synthesis occurs [5’-3’ / 3’-5’].
5’-3’
To produce a complementary strand, the original DNA strand must be read [5’-3’ / 3’-5’] to produce a new 5’-3’ strand.
The original DNA strand must be read 3’-5’ to produce a 5’-3’ nascent strand.
T/F:
Both strands, leading and lagging, are replicated in long, continuous strands.
false
“Both strands, leading and lagging, are replicated in long, continuous strands.”
Correct the above statement.
One strand is made continuously; the other strand is made in discontinuous fragments
What is the leading strand?
the strand of DNA that is being replicated continuously. It is the strand that is being continuously polymerized towards the replication fork.
What direction does the lagging strand grow in?
opposite to the unzipping of the replication fork
The lagging strand is made in fragments.
What are these fragments called?
Okazaki fragments
Why is the lagging strand made in fragments?
Because the strand is growing away from the replication fork, it needs to be replicated in fragments because the Primase (that adds the RNA primer) has to wait until the fork opens further to be able to put the primer.
What are bacteriophages?
virus that infects bacteria
What is capsid?
protein coat containing nucleic acids of virus
Which viruses often have an eicosehedral capsid?
Bacteriophages and
most animal viruses
most viruses that infect eukaryotes are engulfed by an _____ process
endocytotic
What are the 2 possible life cycles of the virus?
lytic cycle and lysogenic cycle.
How are viruses different from living things?
VIRUS not living cuz:
- -do not contain both DNA and RNA
- -have either DNA OR RNA
- -don’t make their own ATP, instead use the host cell’s ATP
Why is there a species barrier against many viral infections?
virus needs specific glycoprotein on host’s cell membrane, in order to enter Host cell.
Different species have different cell membranes with different glycoproteins. This is why there’s the species barrier against viral infections.
What’s a Virulent virus?
virus that follows the lytic life cycle
What’s the other category of virus, other than virulent viruses?
Temperate viruses
What is a temperate virus?
virus in a lysogenic life cycle
What does a virus do after attaching to a cell membrane?
After attaching to cell membrane, virus either
injects nukes directly into cell, or
for animal viruses, is taken into cell through endocytosis
Describe briefly the lytic cycle.
Summarize the lytic life cycle.
Lytic cycle – the viral nucleic acids and enzymes immediately take over the reproductive functions of the cell, start making virions. Cell swells with virions and bursts, releasing virions into external environment.
Summarize the lysogenic cycle.
Lysogenic cycle – the virus’ nukes are incorporated into host cell genome. Host cell makes copies of the viral nukes as it naturally reproduces.
What’s a provirus?
Provirus – name of viral DNA that is embedded in host DNA
Can a virus have single stranded DNA?
Can a virus have double-stranded RNA?
Virus classified by type of nuke it produces.
It can have either single, or double-stranded DNA. Or
it can have either single- or double-stranded RNA.
What is meant by ‘Plus-strand RNA’ or ‘positive-sense’ RNA’?
some viruses have plus-strand RNA, meaning the RNA can be directly translated into protein
What is meant by MINUS-strand (negative sense)** **RNA?
has to be transcribed into positive-sense RNA (by an RNA polymerase) before it can be translated.
What is Reverse transcriptase?
enzyme carried by Retroviruses to create DNA from its RNA, by reverse-transcribing RNA into DNA for incorporation into host-cell’s genome
What is the most famous retrovirus?
HIV
what happens to the DNA created by a retrovirus?
DNA is incorporated into genome of host cell
measles, rabies, flu, are all [plus/minus]-strand RNA viruses
MINUS
what is Positive-sense (plus-strand RNA) analogous to?
viral mRNA
What are Viroids?
infectious pieces of naked RNA in ring form; infect only plants
What are Prions?
naked proteins that cause infections in animals; CAN REPRODUCE themselves w/o DNA or RNA
What is Monera?
a now-obsolete taxonomic group in biological classification originally understood as one of five biological Kingdoms.
The kingdom Monera included most organisms with a prokaryotic cell organization (that is, no nucleus). For this reason, the kingdom was sometimes called Prokaryota or Prokaryotae.
Under the three-domain system of taxonomy established in 1990, the organisms formerly within Monera have been divided into two Domains, Archaea and Bacteria (with Eukaryote as the third domain).
What makes Prokaryotes distinct from eukaryotes?
no membrane-bound nucleus
What are the 2 domains that now make up the old-fashioned grouping called Prokaryotes?
bacteria and
archaea
What is the difference between archaea and prokaryotes?
archaea cell walls not made of peptidoglycan
the 2 domains that now make up the old-fashioned grouping called Prokaryotes, are bacteria and archaea.
What is the difference between archaea and bacteria?
archaea cell walls not made of peptidoglycan
What are Virions?
metabolically inactive form of the virus
What are the names of the major shapes of bacteria?
The major shapes of bacteria are coccus Cocci (round) or bacillus bacilli (rod shape)
Besides cocci and bacilli, what are other bacterial shapes?
Other bacteria shapes are
- spirilla (twists like a spiral),
- vibrio (a curved rod shape or “comma” shape), and
- spirochetes
what are the main components of a phospholipid?
A phosphate group,
2 fatty acid chains, and a
glycerol backbone
T/F: Phospholipids are amphipathic
true
which part of the phospholipids is polar, and which nonpolar?
Phosphate group = polar;
fatty acid chain = nonpolar
proteins that punch through both bilayers are called _______
Integral proteins, or intrinsic proteins
proteins that pierce only one layer of the phospholipids bilayer are called _____
Peripheral or extrinsic proteins
the carbohydrate portion of a glycoprotein always protrudes towards the [inside/outside] of the cell.
outside
each layer of the bilayer is called a _____
leaflet
what’s passive diffusion?
something moves across the membrane in the direction of its electrochemical gradient
w/o use of a specific protein channel,
w/o expenditure of additional energy
The more charge a molecule has, the [harder/easier] it is to passively diffuse across membrane
harder
Can facilitative diffusion be in any particular direction?
Facilitative diffusion – must be in direction of electrochemical gradient of the molecule being transported
______ transport = against electrochemical gradient
active transport goes against the electrochemical gradient
Is the Sodium-potassium pump an example of active or facilitative transport?
active
What does the sodium-potassium pump do?
3 Na out of cell,
2 K into cell
(1 ATP expended)
What is Peptidoglycan / murein?
Peptidoglycan, also known as murein, is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of bacteria (but not Archaea), forming the cell wall.
When saying ‘gram positive’, what part of the bacteria gets stained?
Staining the peptidoglycan cell walls
what color is a Gram positive stain?
dark purple
What color is a gram negative stain?
pink
What are Fimbria?
[microbiology]
short tentacles possessed by many gram-negative bacteria.
Not involved in motility.
Flagella is made from a protein called _____
flagellin
in bacteria, flagella are powered by ______
proton pump
What’s Chemotaxis?
Chemotaxis is the phenomenon in which somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment.
what’s a plasmid?
Small circles of DNA that exist and replicate independently of the bacterial chromosome
what is the method employed by Bacteria to reproduce?
Bacteria reproduce by Binary fission
what are the methods by which bacteria recombine their genes?
Recombine their genes through conjugation, transformation, transduction
conjugation, transformation, transduction
in which of the above 3 methods is f-plasmid involved?
conjugation
What is bacterial conjugation?
Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells.
What is an F plasmid?
A type of fertility factor or F-factor
what’s a fertility factor?
Fertility factor (also known as the F factor, or sex factor) is a bacterial DNA sequence that allows a bacterium to produce a sex pilus necessary for conjugation.
A common form of F-factor is an F-plasmid
In bacteriology, What’s transformation?
pick up naked DNA from outside environment
What’s transduction?
transfer of genetic information thru vector, such as virus
what’s an Endospore?
a dormant, tough, and temporarily non-reproductive structure produced by certain bacteria;
Endospores enable bacteria to lay dormant for extended periods, even centuries.
What are autotrophs?
can fix CO2 and use it as carbon source
What are the opposite of autotrophs?
Heterotrophs
What are chemotrophs?
use oxidation of organic or inorganic matter as energy source
What are Lithotrophs?
Some types of bacteria that use inorganic matter source for electrons
What are organotrophs?
type of chemotroph that gets electrons from organic matter
What does it mean to say that all fungi are exodigestors?
All fungi are exodigestors – spit on food, lie in it, and absorb nutrients
what does Saprophytic mean?
eats dead stuff
Fungus have Cell walls made from a polysaccharide called _____
chitin
Do fungus do asexual or sexual reproduction?
Can do asexual and sexual reproduction
Each turn of the Krebs cycle produces these molecules:
ATP;
FADH2
NADH
A glycolysis reaction produces these molecules:
ATP
NADH
Pyruvate
Minus-strand (i.e., negative-sense) RNA is transcribed into plus-strand RNA by this protein:
an RNA polymerase
most fungi are [unicellular/multicellular]
multicellular
What is hyphae?
A hypha (plural hyphae) is a long, branching filamentous structure of a fungus.
In most fungi, ___ are the main mode of vegetative growth
hyphae
Hyphae are collectively called :
mycelium
nuclear pores allow ___ to pass freely to and from cytosol
RNA
what happens inside a nucleolus
ribosomal subunits assembled;
rRNA transcribed
What are the 3 types of endocytosis?
phagocytosis,
receptor-mediated endocytosis,
pinocytosis
The bag that forms as a result of phagocytosis is called _________
phagosome
what are mitotic spindle fibers made from?
Tubulin
(EK bio 77)
in vertebrates, phagocytosis is seen more with ____.
WBC
What’s the word associated in pinocytosis?
invagination
Which cells can do pinocytosis?
most cells do pinocytosis
What is receptor mediated endocytosis?
R-M endocytosis refers specifically to uptake of macromolecules,
e.g. hormones and nutrients
Cholesterol is taken in to cell, by what type of endocytosis?
R-M endocytosis
rough ER is also called _______
granular ER
A series of flattened, membrane bound sacs in the cell are called ____
Golgi complex
What role does the Rough ER play?
The ribosomes on the rough ER translates proteins;
mRNA of proteins binds to free ribosomes
ribosome-mRNA complex is commonly attached to:
Rough ER
What happens to proteins after they are made on the ER?
proteins carried from ER to golgi apparatus
Each layer or compartment of the golgi apparatus is called a _______
cisterna
What does the Golgi do?
Organizes and concentrates the proteins;
golgi also makes lysosomes
What does the smooth ER do?
smooth ER – Lipid synthesis, including steroids;
packages proteins;
smooth ER in liver – detoxes many poisons;
assists in controlling calcium ion concentration
What does the smooth ER in liver do?
detoxes many poisons;
assists in controlling calcium ion concentration
What is cytoskeleton?
What’s it made of?
A cellular scaffolding or skeleton contained within a cell’s cytoplasm.
It consists of a Network of filaments and tubules
What do microfilaments do?
They squeeze membrane together in phagocytosis and cytokinesis;
They produce the contracting force in muscles;
involved in cytoplasmic streaming (amoeba movement)
What do microfilaments do in muscles?
They produce the contracting force in muscles
What is the important role of microfilaments in amoeba?
involved in cytoplasmic streaming (amoeba movement)
Which are larger: microtubules or microfilaments?
Microtubules
What are microtubules?
Rigid hollow tubes involved in flagella and cilia construction
What protein makes up microtubules?
Tubulin
what’s an axoneme?
The cytoskeletal structure of eukaryotic flagella
what arrangement does the axoneme consist of, specifically?
9 + 2 arrangement
Describe the 9 + 2 arrangement.
Nine pairs of microtubules forming a circle around 2 long microtubules
What is dynein?
Protein in flagella that that acts as a bridge that connects the 9 microtubules (of an axoneme) to each other
T/F:
the 9 + 2 arrangement is seen with both prokaryotes and eukaryotes.
False.
Only with eukaryotic flagella
What is prokaryotic flagella made of?
A protein called flagellin
what’s a centrosome?
What is its function?
an organelle that serves as the main microtubule organizing center (MTOC) of the animal cell
what’s a centrosomes made of?
Centrosomes are composed of two orthogonally arranged centrioles.
what do centrioles do?
Make mitotic spindle fibers
Involved in production of flagella and cilia
what protein makes up microfilaments?
Actin
The three types of cellular jcns that connect animal cells are:
tight jcns,
desmosomes, and
gap jcns
what are tight jcns?
Form watertight seal from cell to cell; blocks water ions and other molecules and fluids.
the part of a cell facing the lumen of a cavity is called the ____ surface
apical
the opposite side of the apical surface is the ______ surface.
Basolateral
What are desmosomes?
Like welds holding the cell together
what are gap jcns?
Tunnels between cells
do mitochondria have RNA?
Yes
Mitochondrial DNA comes from the [father / ** mother / both]**
mother
Mitochondria have [1 / 2] phospholipids layers.
2 phospholipid bilayers
What is basal lamina?
What is its function?
Thin sheet of extracellular matrix that separates epithelial cells from support tissue.
What does basement membrane refer to?
Same thing as basal lamina
what is collagen?
Structural protein found in extracellular matrix; gives cartilage and bone their strength
(1) what’s a glycocalyx?
(2) Where is it located?
(3) What pathology is it involved in?
–Animal analogy to plants’ cell wall;
–separates cell membrane from extracellular matrix.
–Cancer cells have abnormal glycocalyx
What are the 4 tissue types?
epithelial,
nervous,
muscle,
connective
What 3 body systems allow for intercellular communication?
nervous, paracrine, endocrine
nervous, paracrine, endocrine
which of the above 3 has the most limited reach?
Paracrine
what is the typical reach of the paracrine system?
A few millimeters
what are the messengers that travel through the nervous system?
Neurotransmitters
what are the messengers that travel through the paracrine system?
Hormones like prostaglandins
What types of tissue are connective?
Blood, lymph, bone, cartilage, adipose, tendons, ligaments
what are the messengers that travel through the endocrine system?
hormones that travel all over the body
The parts of a neuron are:
dendrites,
cell body soma,
axon,
axon terminal
What do the dendrites do?
Receive signal to be transmitted
what’s an axon?
The long, slender “tunnel” part of a neuron
What’s an axon hillock?
The part of a nerve cell that connects the soma with the axon
what’s a soma (when talking about neurons)?
The part of the neuron that has the nucleus, and from which the dendrites branch out.
The nerve signal travels a neuron from its _______ to its _______
from the dendrites to the axon hillock, where an action potential is generated and moves down the axon to the axon terminal synapse
What’s the action potential of neuron?
Disturbance in the electric field across the membrane of a neuron
What’s resting potential?
b/c of the work of the Na/K pump (among others), the neuron has a positive charge on the outside; and a negative charge on the inside of the cell membrane. So there’s an electric potential difference (voltage) across the cell membrane
What causes the resting potential in neurons?
b/c of the work of the Na/K pump (among others)
Where is the positive charge on a neuron?
Where is the negative charge on a neuron?
Positive charge is outside the cell
Negative charge is Inside.
What kind of genetic material do measles, rabies, and flu viruses have?
minus-strand RNA
in the neuron, an action potential begins at the _____
axon hillock
in neurons, what does all-or-nothing mean?
Action potentials are all-or-nothing. Meaning, the neuron’s cell membrane completely depolarizes, or ELSE no action potential is generated at all.
threshold potential is AKA:
threshold stimulus
What’s threshold potential?
the minimum stimulus needed, to generate an action potential
what’s Brownian motion?
Random motion of molecules
what are the types of synapses?
Chemical and electrical
which synapse is faster?
electrical
what is an electrical synapse?
Gap jcns between cells.
which cells have electrical synapses?
Cardiac muscle,
visceral smooth muscle,
very few neurons in the CNS
which synapse(s) are unidirectional?
Chemical synapse
the slowest step in the transfer of a nervous signal from one neuron to another is:
at the synapse
what other nervous cells exist other than neurons?
Glial cells, or
neuroglia
which are more abundant in humans, glial cells or neurons?
Glial cells
what is myelin?
Electrically insulating sheaths
what cells produce the myelin for the PNS?
Schwann cells
what advantage does myelin give to neurons?
Increases speed at which an axon can transmit signals
Do all living things have myelinated axons?
Only vertebrates
explain what white matter and gray matter refers to.
Myelinated axons appear white; nervous system cell bodies appear gray
on an axon, the gaps between myelin sheaths are called _____
nodes of Ranvier
What is noteworthy about the nodes of Ranvier?
the action potential jumps from one node to the next; this is called saltatory conduction
For the MCAT, what does “sympathetic” and “parasympathetic” mean?
sympathetic → fight or flight
parasympathetic → rest and digest
What specific branch of the nervous system are sympathetic and parasympathetic a part of?
They are under the autonomic branch of the NS
What is the other branch of the PNS, besides autonomic?
Somatic
under what branch of the PNS is “sensory” and “motor” seen?
both the autonomic branch AND the somatic branch
where are rod cells and cone cells found?
On the retina
the pigment on rod cells is called ____
rhodopsin
which cell distinguishes colors?
cones
what part of the ear is responsible for balance?
Semicircular canals
what part of the ear turns sound waves into neural signals that are sent thru the nerves into the brain?
Organ of Corti
CNS refers to:
brain and spinal cord
Another NAME for the somatic nervous system:
voluntary
the involuntary nervous system is AKA:
autonomic
visceral
the voluntary nervous system is AKA:
somatic
[exocrine/endocrine] glands release hormones into external environment thru ducts
exocrine
[endocrine/exocrine] glands release hormones directly into bloodstream in the capillaries
endocrine
sweat, oil, mucous, and digestive glands are all examples of [endocrine/exocrine] glands
eXocrine
All hormones work by binding to proteins called ______
receptors
What is the endocrine system responsible for?
endocrine system regulates:
metabolism,
growth and development, and
reproduction
What are the 3 basic classes of hormones?
peptide hormones,
steroid hormones, and
tyrosine derivatives
where inside the cell, are peptide hormones made?
made in rough ER; then sent to Golgi
In its initial stages, when a hormone is just made by the ER, what is it called? What form is it in?
preprohormone
how does a cell that manufactured a hormone, release it?
cell is stimulated by other hormone OR by nervous system,
cell releases hormone thru exocytosis of secretory vesicle
T/F:
peptide hormones are water soluble, so they dissolve in blood and blood carries them to destination
TRU
What’s an effector?
The target cell of a hormone; the cell that the hormone is intended to affect
when a peptide hormone arrives at a target cell, how does it enter the cell? Or does it enter the cell at all?
Hormone doesn’t diffuse thru membrane;
instead, binds to receptor on the membrane
what’s an intracellular second messenger?
What does it do?
Chemicals that respond to hormone (the 1st messenger) by activating/deactivating enzymes and/or ion channels to create a series (“cascade”) of chemical reactions
Common second messengers include:
cAMP;
cGMP; and
calmodulin
steroid hormones are often derived from and are chemically similar to ______
cholesterol
Steroid hormones are [carbohydrates/lipids/proteins]
lipids!
T/F:
steroid hormones are water soluble, so they dissolve in blood and blood carries them to destination
usually false.
Steroids are lipids, so they require a protein transport molecule to be able to travel thru blood stream
T/F:
steroids diffuse thru the cell membrane of the effector.
tru
the 3 stuctures or organs within the body, that produce steroid hormones are :
placenta,
gonads,
adrenal cortex
What are the 2 tyrosine hormone groups that we have to know?
thyroid hormones, and
catecholamines
name the thyroid hormones.
Thriiodothyronine; and
thyroxine
name the catecholamines.
epinephrine,
norepinephrine,
and
dopamine
What’s another name for thyroxine?
T4
What are the groups of peptide hormones we have to know for the MCAT?
4 large groups:
Anterior pituitary hormones (8 hormones);
Posterior pituitary (2 hormones);
the parathyroid hormone PTH (1);
the pancreatic hormones (2)
What are the important Steroid hormones we must know for the MCAT?
2 major groups:
Adrenal cortex hormones (glucocorticoids and mineral corticoids)
[the specific mineralocorticoid we should know is aldosterone];
[the major glucocorticoid we should know is cortisol];
and the gonadal hormones
Where are the catecholamines formed?
Adrenal medulla
What type of hormone are the catecholamines? Steroid, peptide, tyrosine?
They’re tyrosine derivatives
epinephrine and norepinephrine are [water/lipid] soluble
water
the thyroid hormones (T3 & T4) are {water/lipid} -soluble
lipid
what does the mnemonic device FLAT PG help you memorize?
The hormones of the anterior pituitary
another name for the anterior pit is _______
adenohypophysis
the adrenal cortex produces {steroid / peptide / tyrosine} hormones
steroid
the thyroid produces {steroid / peptide / tyrosine} hormones.
tyrosine (e.g. T3 & T4) and peptide (calcitonin) hormones
the adrenal medulla produces [steroid / peptide / tyrosine] hormones
catecholamines, which are tyrosine derivatives
How does the hypothalamus control the anterior pituitary?
It controls the pituitary by releasing hormones of its own that it sends to the pituitary.
what blood supply connects the hypothalamus with the pit gland?
Hypophyseal portal system – blood vessels from hypothalamus to anterior pituitary
How many hormone are made and released by the anterior pituitary?
8
List the 8 anterior pituitary hormones.
FLAT PEG =
FSH – follicle-stimulating hormone
LH – leutinizing hormone
ACTH - adrenocorticotropin
TSH – thyroid-stimulating hormone
Prolactin
beta-Endorphins
hGH – human Growth hormone
& MSH - melanocyte stimulating hormone
the pituitary releases [peptide / lipid /tyrosine-derivative] hormones.
Pit makes peptide hormones
Another name for human growth hormone is ______.
somatotropin
What does hGH do?
Stimulates growth of almost all cells of body.
Increases mitosis, Increases transcription and translation.
how is hGH unique among the hormones of the ant pit?
It doesn’t have a specific target tissue, unlike the other ant pit hormones
What does the ACTH do?
stimulates adrenal cortex to release glucocorticoids
what mechanism does ACTH use to stimulate the adrenal cortex?
Stimulates the adrenal cortex via the 2nd messenger system using cAMP
What does the TSH do, specifically?
stimulates thyroid to release thyroxin and triiodothyronine
How does the TSH stimulate the thyroid?
Using the 2nd messenger system using cAMP
What does prolactin do?
Promotes milk production (NOT release of milk)
What is another name for vasopressin?
ADH
Why is the post. pit. called the neurohypophysis?
it is largely a collection of axonal projections from the hypothalamus that terminate behind the anterior pituitary gland.
T/F:
the post pit makes hormones.
False:
Post pituitary hormones made in hypothalamus, but released from post pit
What hormones does the post pit release?
ADH and
oxytocin
What’s somatotropin?
hGH
What does oxytocin do?
uterine contraction during pregnancy and
milk LETDOWN/ejection
What does ADH do?
↑↑ blood pressure; &
affects water absorption by kidney
aldosterone is a _____corticoid
mineralocorticoid
What does aldosterone do?
Acts in the kidneys to:
↓↓ Na excretion;
↑↑ K excretion
↓↓ Water excretion
What does cortisol do?
↑↑ blood glucose levels (by stimulating gluconeogenesis in the liver);
↓↓ bone formation;
↓↓ the immune system’s B-cell mediated response to inflammation
What’s gluconeogenesis?
Creation of glucose and glycogen in the liver
What is the fcn of the thyroid hormones?
Increase BASAL METABOLIC rate.
what’s basal metabolic rate?
The resting metabolic rate
What are the Islets of Langerhans?
The islets of Langerhans are the regions of the pancreas that contain its endocrine (i.e., hormone-producing) cells
What does calcitonin do?
Lowers blood calcium
Is the pancreas an endo- or exocrine gland?
Both
what two important hormones are released by the pancreas?
Insulin and
glucagon
what cells of the pancreas release insulin?
Beta cells
What does insulin do?
Promotes entry of glucose into cells; thereby ↓↓ blood glucose level
what hormone has nearly the opposite effect of insulin?
glucagon
What cells of the pancreas release glucagon?
Alpha cells
what does glucagon do?
↑↑ gluconeogenesis and Glycogenolysis;
↑↑ blood glucose level
How many parathyroid glands exist?
4
what hormone does the parathyroid gland release?
PTH
What does PTH do?
↑↑↑ concentration of Ca ions in blood
what hormone has the opposite effect of parathyroid hormone?
calcitonin
where does sperm production occur?
Seminiferous tubules
In response to FSH, what occurs in the body?
(DESCRIBE specific)
Growth of ovarian follicles in females;
Males: FSH stimulates **primary spermatocytes** to undergo the first division of meiosis, to form secondary spermatocytes.
FSH acts synergistically with ___ hormone
LH
what does LH do?
Luteinizing hormone causes ovulation;
In females, an acute rise of LH called the LH surge triggers ovulation and development of the corpus luteum.
In males, where LH had also been called interstitial cell-stimulating hormone (ICSH), it stimulates Leydig cell production of testosterone.
what is estradiol?
A sex hormone, a type of estrogen
What does estradiol do?
Prepares the uterine wall for pregnancy
most estradiol in women is produced by the ___ cells.
the granulosa cells of the ovaries
the luteal surge is an example of ____ feedback
positive feedback
What’s the zona pellucida?
The zona pellucida (plural zonae pellucidae) is a glycoprotein membrane surrounding the plasma membrane of an oocyte.
what’s an oocyte?
An immature ovum
When an egg is released from the ovary, the follicle surrounding it becomes the ______
corpus luteum
What does the corpus luteum do?
Secretes hormones thru pregnancy
if there is no pregnancy, what happens to corpus luteum?
Degrades into corpus albicans
what are the Leydig cells?
Where are they found?
What are they AKA?
And what is their fcn?
Leydig cells, also known as interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle.
They produce testosterone in the presence of luteinizing hormone (LH)
where in the body is sperm made?
Seminiferous tubules
what does androgen mean?
Any natural or synthetic compound stimulates or controls the development and maintenance of male characteristics
what are the organs that contribute to seminal fluid?
Seminal vesicles;
prostate; and
bulbourethral gland
what are the Cowper’s glands AKA?
AKA bulbourethral gland
what is the function of prolactin?
PROlactin – milk PROduction
what are the 3 stages of the menstrual cycle?
Follicular phase;
luteal phase; and
flow
when does the follicular phase begin?
When does it end?
Begins with the development of the follicle and ends at ovulation
describe the luteal phase.
Luteal phase begins with ___ and ends with ___.
Begins with ovulation and
ends with degeneration of corpus luteum into corpus albicans
describe flow phase
3 days of shedding of uterine lining
where in the body does fertilization take place?
Fallopian tubes
what’s the acrosome?
Bag of enzymes on the head of sperm
when the nuclei of the sperm and ovum unite, the new cell is called a ______.
zygote
what’s a morula?
When zygote is composed of 8 or more cells
what’s a blastocyst?
The zygote turns into a blastocyst, a Hollow ball filled with fluid.
by the time the baby attaches to the mother’s uterus, it’s called a :
blastocyst
what hormone does the fertilized egg secrete after it implants in mother?
HCG
what does HCG stand for?
Human chorionic gonadotropin
what is the function of HCG?
Prevents degeneration of corpus luteum
why is the corpus luteum maintained?
So that the corpus can continue secreting estrogen and progesterone
what does a pregnancy test, test for?
for HCG in the urine and blood of the mother
what’s physically in the way of the sperm getting into the oocyte?
The granulosa cells and
the zona pellucida
what does the blastocyst turn into?
Gastrula
what happens during gastrulation?
Cells begin to move around. In mammals, a primitive streak is formed. The 3 primary germ layers are formed
what’s a primitive streak?
Why is it important?
[The primitive streak is a structure that forms during the early stages of avian, reptilian and mammalian embryonic development.]
During the early stages of development, the primitive streak is the structure that will establish bilateral symmetry, determine the site of gastrulation and initiate germ layer formation.
name the 3 primary germ layers:
ectoderm;
endoderm;
mesoderm
what does the ectoderm give rise to?
Over coverings of body, like:
skin (epidermis),
nails,
tooth enamel, AND
nervous system
the eye,
inner ear, and,
as neural crest cells, to many connective tissues of the head
what does the endoderm turn into?
bladder
Liver,
Lungs,
pancreas, and
Lining of digestive tract/ alimentary canal
what does mesoderm turn into?
“the stuff between the inner and outer covering of body:
muscle, bone, and the rest”**
**these are guidelines for the MCAT, NOT fixed rules
what does the gastrula turn into?
And what is that process of turning, called?
Gastrula undergoes neurulation to become neurula
(1) what is the notochord?
(2) From what embryonic layer does it arise?
(3) What is its purpose?
The notochord is a flexible, rod-shaped body found in embryos of all chordates.
It is composed of cells derived from the mesoderm and defines the primitive axis of the embryo.
When does the neural plate form?
In human embryology, formation of neural plate is the first step of neurulation. It is created by a flat thickening opposite to the primitive streak of the ectoderm.
Does sound have the same speed through monoatomic gases, diatomic gases, and polyatomic gases?
Given the same pressure and gas density, monoatomic gases permit sound to travel thru at greater speed than diatomic and polyatomic gases.
Does sound have the same speed through a gas, regardless of its temperature?
Sound travels faster through hotter air than colder air
(TBR Physics Book 2, page 5)
When we talk about sound, what does pitch mean?
The frequency of that sound
where does the digestion of protein begin in the body?
Stomach
Where are the crypts of Lieberkühn found?
Small intestine and
colon
where does the digestion of carbs begin in the body?
mouth
what is digested in the esophagus?
Nothing
the 3 sections of the Small intestine are:
duodenum, jejunum, ileum
what’s chyme?
The fluid that the stomach turns food into
what’s the pH of a full stomach?
2
the 4 major cell types in the stomach are :
mucous cells;
chief cells;
parietal cells; and
G cells
chief cells are AKA?
Peptic cells
parietal cells are AKA?
Oxyntic cells
what does the G cell do?
Secretes gastrin
where in the digestive system are goblet cells found?
Small intestines and
colon
what is gastrin?
a peptide hormone
what does gastrin do?
Stimulate secretion of HCl in stomach
what nutrients are absorbed in the stomach?
No absorption occurs in the stomach
what are chief cells AKA?
Peptic cells
what do chief cells do?
releases pepsinogen and
gastric lipase
what is pepsinogen?
The precursor to pepsin
what is pepsin?
Enzyme that breaks down protein
what do parietal cells do?
Secrete HCl
where does most of the digestion take place in the digestive system?
Small intestine
what’s a lacteal?
Where is it found
The lymphatic vessel inside each villus of the small intestine
what does the lacteal do?
Absorb fat
what do goblet cells do?
Secrete the precursor to mucus
what do the crypts of Lieberkühn secrete?
secrete various enzymes, including
peptidases,
sucrase, maltase, lactase and
intestinal lipase
what thing prevents food from entering the lungs?
Epiglottis
why is the pH of the duodenum different from the stomach?
Presence of bicarbonate ion
where does the bicarbonate ion in the duodenum, come from?
Secreted by pancreas
what is the pH of the duodenum?
6
what are the enzymes released by the pancreas into the small intestine?
Trypsin(ogen),
chymotripsin(ogen),
elastase,
carboxypeptidase,
pancreatic amylase,
lipase,
phospholipase,
ribonuclease, and deoxyribonuclease
what does trypsin do?
Degrade proteins into polypeptides
what does chymotripsin do?
cleaves peptide bonds where the carboxyl side of the bond (the P1 position) is a hydrophobic amino acid (tyrosine, tryptophan, or phenylalanine)
where is bile stored?
Gall bladder
where is bile made?
Liver
through what opening/path does the gall bladder release bile?
Cystic duct
What pathway connects the pancreas to duodenum?
Pancreatic duct
what is the healthy bacteria in the colon?
E. coli
what food that we eat contains chitin?
mushrooms
is sucrose a mono- or disaccharide?
di-
what 2 monos make up sucrose?
glucose and
fructose
what 2 monos make up lactose?
glucose and
galactose
when the liver metabolizes fat or protein for energy, blood acidity [increases/decreases/stays the same]
increases
the major osmoregulatory protein in the blood is ___
albumin
the Bowman’s capsule and the glomerulus together are called the ____.
renal corpuscle
the fcn of the renal corpuscle is ___.
filtration
the fcn of the distal tubule is to ____.
The net effect of this is to:
to reabsorb Na and Ca but secrete K, H, and bicarb anion.
Net effect: to ↓↓ filtrate osmolarity
fcn of the proximal tubule is ____.
reabsorption
trace the step by step PATHway of liquid thru a nephron.
Glomerulus → Bowman’s capsule → proximal convoluted tubule → descending part/limb of the loop of Henle → thin ascending limb of the loop of Henle → thick ascending limb of the loop of Henle → Distal convoluted tubule → collecting duct → renal calyx → renal pelvis
what does the juxtaglomerular apparatus do?
Monitors filtrate pressure in the distal tubule
the fcn of the loop of Henle is _____.
to ↑↑ the solute concentration and thus:
creates a concentration gradient in the renal medulla
↑↑ osmotic pressure of the renal medulla
List 8 fcns of the liver.
blood storage,
filtration,
detoxification,
RBC destruction,
bile production,
metabolism of carb and protein and fat
what are the fcns of the kidney?
filtration/excretion,
homeostasis,
control of plasma pH
what hormones act on the distal tubule?
ADH and
aldosterone
where is fluid pressure (hydrostatic) the greatest in the blood circulatory system?
Straight out of the left ventricle
(1) where in the body is fluid (hydrostatic) pressure the weakest?
(2) Why is it the weakest at that location??
As blood enters vena cava.
Reason: hydrostatic pressure ↓↓ from aorta to vena cava. Pressure goes ↓↓ the farther away from the ventricles.
where is blood flow the slowest?
Speed of blood lowest at capillaries
trace the PATHway of blood thru the blood vessels as it enters the heart as deoxygenated blood.
Vena cava empty into right atrium →
tricuspid valve →
rt vent →
pulmonary semilunar valve →
pul arteries → arterioles (in lung) → caps (@ alveoli) →
venules (in lung) → veins (in lung) → pulmonary veins →
left atrium → bicuspid valve → left ventricle →
aortic semilunar valve
What specific part within the heart triggers heart contraction?
SA node
where is the SA node located?
in right atrium
What nerve triggers the SA node?
SA node innervated by vagus nerve; BUT, SA node contracts all by itself!
what does vagus nerve do to SA node?
Slows the contractions of the SA node
is the vagus nerve part of the symp or parasymp nervous system?
a parasympathetic nerve
if you sever the connection between the vagus nerve and the heart, will the heart rate [increase/decrease/no effect]?
Cut vagus nerve, and heart rate will increase
trace the PATH of an action potential from the SA node thru the rest of the heart:
SA node → AV node → bundle of His → Purkinje fibers → cardiac muscles
where’s the bundle of His located?
In the wall separating the ventricles
where’s the location of Purkinje fibers?
located in the inner ventricular walls of the heart,
just beneath the endocardium.
What are Purkinje fibers?
Their fcn?
These fibers are specialized myocardial fibers that conduct an electrical stimulus or impulse that enables the heart to contract in a coordinated fashion.
a ______ carries blood away from the heart.
Artery
what part of the brain controls the diaphragm?
Medulla oblongata
how many polypeptide units make up hemoglobin?
4
how many heme cofactors does each polypeptide subunit of hemoglobin have?
1 per polypeptide
what’s a heme cofactor?
Organic molecule with iron atom at its center
how many heme cofactors does hemoglobin have?
4
what does an oxygen dissociation curve graph basically show you?
The oxygen saturation of hemoglobin
What can affect an oxygen dissociation curve?
CO2 pressure,
pH, and
blood temp
What does ↑↑ the CO2 do to the oxygen dissociation curve?
Curve shifts to the right
What does ↑↑ the pH do to the oxygen dissociation curve?
Curve shifts to the left
What does ↑↑ the temperature do to the oxygen dissociation curve?
Curve shifts to the right
What does a shift to the right, in the oxygen dissociation curve, signify?
↓↓ of hemoglobin’s affinity for oxygen
If CO2 leaves the body, how is blood pH affected?
pH increases ↑↑
(CO2 + water → bicarb anion + proton)
what is hematocrit?
Percentage by volume of red blood cells
what is albumin? Its fcn?
Protein found in blood plasma, that
regulates osmotic pressure of blood; and
transports fatty acids and steroids
what’s serum?
blood Plasma from which fibrinogen was removed
what lives longer:
granulo- or agranulocytes?
Agranulocytes live very long time,
granulocytes very short time
which are the granular leukocytes?
B.E.N.
what is the most abundant of the 5 leukocytes?
Neutrophils
What’s the 2nd most abundant leukocyte?
Lymphocytes
What’s an antigen?
ANTIbody GENerator
Foreign particle in body
list the agranulocytes:
lymphocytes and monocytes
What are the 4 possible functions of muscle?
Body movement;
stabilization of body position;
movement of stuff thru body; and
generating heat to maintain body temperature
what does tendon do?
Connects muscle to bone
what is a ligament?
Connects bone to bone
what is an agonist?
Muscle responsible for the movement
what is an antagonist?
Muscle that works against the agonist
what’s a sarcomere?
Smallest func’nal unit of skeletal muscle
starting from a muscle, what are the parts of a muscle, right down to the individual sarcomere’s components?
(ignore the sheats, like perimysium and epimysium)
Muscle → muscle fasciculus → muscle cell → myofibril → sarcomere → thick and thin filament
what’s a sarcolemma?
the cell membrane of a striated muscle “fiber” (i.e., muscle cell)
[T/F] a muscle fiber and myofibril are the same thing.
F.
Several myofibrils (bound together by the sarcolemma) form a muscle cell. Muscle cell is the same thing as muscle fiber.
How many nuclei do cardiac muscle cells contain?
1
How many nuclei do skeletal muscle contain?
multiple
How many nuclei does smooth contain?
1
What are the functions of bones?
Support of soft tissue;
protection of internal organs;
movement;
mineral storage;
blood cell production;
energy storage
What do osteblasts do?
Secrete collagen and organic compounds on which bone is formed.
can osteblasts do mitosis?
no
from what cells do osteoblasts develop from?
Osteogenic/osteoprogenitor cells
what do osteocytes do?
Exchange nutrients and waste materials with blood
what are osteoclasts?
Reabsorb bone matrix
the long shaft of a long bone is called?
Diaphysis
what marrow does spongy bone contain?
red
in adults, what bone marrow does the compact bone house?
Yellow bone marrow
what are the 4 types of bones?
Long, short, flat, or irregular
list the fcns of the skin.
Blood reservoir;
Environmental sensory input;
excretion;
immunity;
Protection;
Thermoregulation;
vitamin D synthesis
what does phenotype mean?
phenotype is an organism’s observable characteristics or traits.
Give examples of phenotype
an organism’s morphology, development, biochemical or physiological properties, behavior, and products of behavior (such as a bird’s nest).
what does genotype mean?
genotype is the genetic makeup of a cell, an organism, or an individual (i.e. the specific allele makeup of the individual) usually with reference to a specific character under consideration.
what does homologous mean?
Homologous chromosomes are chromosome pairs of the same:
length,
centromere position, and
staining pattern,
and have genes for the same characteristics located at corresponding loci.
How are homologous chromosomes inherited?
One homologous chromosome is inherited from the organism’s mother; the other from the organism’s father.
what is a diploid?
Diploid (indicated by 2n = 2x) cells have two homologous copies of each chromosome (i.e., a homologous pair), usually one of the homologues coming from the mother and the other homologue chromosome from the father.
So for any 1 trait, a diploid individual will have 2 chromosomes, each containing a separate gene that codes for that specific trait.
[these 2 chromosomes are called HOMOLOGOUS]
what does “complete dominance” mean for diploids?
Complete dominance occurs when the phenotype of a heterozygote is completely indistinguishable from the phenotype of a dominant homozygote.
what’s an allele?
2 or more forms of a particular gene.
Diploid organisms have one copy of each gene (and therefore one allele) on each chromosome.
If both alleles are the same, they are homozygotes. If the alleles are different, they are heterozygotes.
What is a homozygote?
Organism with homozygous alleles
What does homozygous and heterozygous mean?
A cell is said to be homozygous for a particular gene when identical alleles of the gene are present on both homologous chromosomes.
A diploid organism is heterozygous at a gene locus when its cells contain two different alleles of a gene.
Heterozygous genotypes are represented by a capital letter (representing the dominant allele) and a lowercase letter (representing the recessive allele), such as “Rr” or “Ss”.
What does karyotype mean?
A karyotype is the number and appearance of chromosomes in the nucleus of a eukaryotic cell.
Karyotypes describe the number of chromosomes, and what they look like under a light microscope.
Attention is paid to their length, the position of the centromeres, banding pattern, any differences between the sex chromosomes, and any other physical characteristics.
Under the new taxonomical classification system, what are the new superkingdoms called?
Domains
list the domains.
Bacteria, Archaea, and Eukarya
which former ‘kingdoms’ are under the new domain eukarya?
Protista, fungi, plantae, animalia
which former kingdom is considered outdated by the new domain system?
Monera. Monera is now split into bacteria and archaea
What hormone stimulates gluconeogenesis in the liver?
Cortisol
ADH [raises / lowers] blood pressure.
raises
Vasopressin causes your body to increase its:
↑↑ peripheral vascular resistance; and
↑↑ arterial blood pressure, and
↑↑ water absorption
Membrane that wraps several myofibrils together to form a muscle cell is called: ?
sarcolemma
What does TCA stand for?
Tricarboxylic acid cycle
