anatomy 1 exam Flashcards
homeostasis
the existence of a stable internal environment.
Maintaining homeostasis is vital to maintaining proper physiological
function and thus crucial for survival.
why is it important to maintain homeostasis?
Organisms (including humans) live in changing and unpredictable
environments.
By maintaining homeostasis (constant internal environment),
physiological functions can proceed in a constant environment and
avoid disruption from environmental influences.
Differentiate between the study of anatomy and the study of physiology.
-Anatomy refers to the internal and external structures of the body and their physical relationships,
- physiology refers to the study of the functions of those structures.
autoregulation.
When a cell, tissue, organ, or
organ system adjusts in response to an environmental
change. Does not involve the nervous or endocrine
systems.
System regulates itself.
Extrinsic regulation
Results from activities of the
nervous system or endocrine
system detecting a change in the
environment and sending
electrical/chemical signal to adjust
activities of another system.
Extrinsic = operating from outside.
Example:
Your nervous system detects a
drop in environmental temperature
and sends signal to muscles to
increase heat production.
difference between auto and extrinisc regulation
auto
- small scale
-system regulates itself
- no nervous and endocrine system
extrinsic
-larger scale
- nervous or endocrine system
negative feedback
Negative feedback opposes
variations from normal (set point).
Most feedback mechanisms in
human body are negative.
homeostatic regulation
Receptor- detects environmental stimulus
control center- receives and processes the information by keeping a set point
effector- Cell or Organ that responds to control center’s
commands.
positive feedback
Positive feedback mechanisms
produce a response that
enhances the original homeostatic
change.
Much less common than negative
feedback mechanisms.
neg feedback
response to the change occurs in real time not over a long period of time. Body immidiatly tries to correct error
matter
anything that takes up space.
mass
the amount of material in
matter (not the same as weight).
volume
the amount of space That matter occupies.
what are atoms composed of
subatomical particles
- protons +
- electrons -
neutrons =
Electrons orbit nucleus in ELECTRON CLOUD.
The number of protons is generally equal to the number of
electrons (results in neutrally charged atom)
atomic number
The number of protons in
the nucleus of an atom
atomic mass
Roughly equal to the
number of protons +
number of neutrons in
nucleus of atom.
Remember: #protons = # neutrons in neutrally charged atom.
For Carbon….Atomic mass = 6 protons + 6 neutrons = 12
element
a pure substance composed of only one
type of atom.
isotopes
atoms of same element that contain
different number of neutrons.
Does not change charge, but does change
atomic mass.
- Thats why the atomic mass of Carbon is not exactly 12
Radioisotopes
isotopes with unstable nuclei that break down and
give off subatomic particles or radiation.
Uses:
Cancer Treatments
Tracers/labeling
Imaging
Medical Diagnostics
Images
(top)
electron orbit, cloud, energy levels
Electrons travel around the
nucleus in defined orbits.
The area that electrons orbit
within is called the electron
cloud.
Within an electron cloud,
electrons occupy an
orderly series of energy levels
orbital energy levels
E1 – lowest energy level.
Can hold up to 2 electrons.
E2 – Can hold up to 8
electrons.
E3 – Can hold up to 8
electrons.
E1 fills before electrons
occupy E2, and so on.
valence shell
valence electrons
outermost energy level of atom
- what the valence shell contains is valence electrons
molecules
Any chemical structure
consisting of atoms held
together by shared
electrons.
compounds
pure chemical substance
made up of atoms of two
or more different
elements in fixed
proportions
molecular weight
the sum of the atomic weights of a molecules
components.
ionic bonds
chemical bonds
formed by the
electrical attraction
Between negatively
and positively
charged ions.
Ionic bonds are
weak (held together
only by electrical
charges attracting)
covalent bond
chemical bonds
formed by atoms sharing electrons
in outer most energy level.
Shared electrons orbit both nuclei
Covalent bonds are strong because
the atoms share electrons
Polar covalent bond and nonpolar
Electrons are shared
unequally.
* Electron spends more
time orbiting one atom.
* Result is one atom has
slightly negative charge
while other has slightly
positive charge.
Non-polar
* Electrons are shared
equally by both atoms.
* Electron spends equal
time orbiting both nuclei.
Rank bonds from weak to strong (1,2,3)
1 Hydrogen bonds the weakest
2 ionic bonds stronger than hydrogen bonding
3 covalent bonds are the strongest
synthesis reaction
increasing the number of bonds (anabolism)… Building more complex molecules from smaller pieces. So the number of bonds increases
decomposition reaction
catabolism… Breaking down larger molecules into smaller pieces. So the number of bonds decreases
exchange reaction
shuffling components of molecules pairing decomposition with synthesis
hydrolysis reaction
decomposition reaction involving water as a reactant
Anabolism
- Anabolism is the process of building up complex macromolecules, such as nucleic acids, proteins, polysaccharides, and lipids.
catabolism
Catabolism is the process of breaking down complex macromolecules into simple molecules, such as carbon dioxide, water, and ammonia.
work
The movement of an
object or change in
physical structure of
matter.
physiological work
Any process that
increases order and
requires energy.
Examples: building
proteins from amino
acids, transporting
solutes across cell
membranes.
kinetic vs potential energy
kinetic- energy that can be transferred to another object to do work
potential- energy that has the potential to do work
Atp
main form of cellular
energy.
Breakdown of ATP to ADP
releases large amounts of
energy that can be used by
cells to perform
physiological work.
Hydrolysis
decomposition involving water. Reversal of dehydration synthesis water is added between two molecules whic is what breaks molecules apart
Dehydration reactions
formulation of
complex molecules by the
removal of water.
two molecules are joined by removal of water
exergonic reaction
Reactions that result
in the net release of
energy.
Relatively common
in the body.
They generate the
heat that maintains
your body
temperature.
endergonic reaction
Endergonic Reactions
Reactions that
result in the net
absorption of
energy.
Examples: the
synthesis of fats and
proteins.
activation energy
the
amount of energy
needed to start a
reaction.
Methods of Activating
Reactions
1. Temperature changes
2. pH changes
3. Enzymes
(methods 1&2 above would
be deadly to cells)
enzymes
promote chemical reactions by lowering the activation
energy required to begin the reactions.
Enzymes belong to class of substances called catalysts.
Enzymes make it possible for chemical reactions to take place under
normal conditions of cells.
important enzyme facts
IMPORTANT!!!
Enzymes affect only the rate at which reactions occur.
Enzymes do not affect the direction that reactions progress or the
products formed.
Enzymes are proteins.
active site
a groove or
pocket in which one or
more substrates can fit.
Substrates fit into active
site like a “lock and key”
based on shape and
charge.
Enzymes fit only specific
substrates (Also known as
“SPECIFICITY”).
saturation limit
the
substrate concentration
required to have the
maximum rate of reaction.
inert have
1) biologically important atoms
2) reactivity
3) abundance
organic compounds
contain C,H
inorganic
dont contain C,H as primary structures may syill contain them
organic compounds examples
Common Examples:
* Methane
* Sugars (glucose C6H12O6)
* Lipids
* Proteins
inorganic compounds examples
Important inorganic
compounds in human
body:
* Carbon dioxide (CO2)
* Oxygen (O2)
* Water (H2O)
read pt 2
Some organic molecules contain
polar covalent bonds, which attract
water molecules and form
hydration spheres (see image to
the right).
These are referred to as
hydrophillic (water loving).
Other organic molecules have no
polar covalent bonds and do not
form hydration spheres.
These are referred to as
hydrophobic (water fearing).
suspension
Contains large molecules
in solution, but if
undisturbed, its particles
will settle out of solution
due to gravity.
* Example: blood
read
Many inorganic compounds are
held together by ionic bonds.
When they come in contact
with negative and positive ends
of water molecules, these
compounds dissociate (break
apart).
Dissociated ions are
surrounded by water molecules
forming hydration spheres.
The result is an aqueous
solution.
colloid
A solution containing
dispersed proteins or other
large molecules.
* Particles will remain in
solution indefinitely
Why is water good solvent?
Polar covalent bonding of H and O
in water molecules creates positive
and negative ends (poles).
heat capacity
the quantity of heat required to raise the temperature of a unit
of mass of a substance 1°C.
why does water have a high heat capacity?
Water has a high heat capacity because of hydrogen bonding among
molecules.
lubrication
Because there is little friction between water molecules, water is an
effective lubricant
salt
an ionic compound that contains any
cation (except H+) and any anion (except OH-)
Salts are held together by ionic
bonds and dissociate in water.
Salts are neutral (do not effect pH)
carbohydrate
an organic molecule that contains C, H, and O in a ratio near
1:2:1
Carbohydrates are:
1. generally water soluble.
2. most important as energy sources that are catabolized.
monosaccharides
Monosaccharides (simple sugars) are carbohydrates with
three to seven carbon atoms.
Disaccharides
two monosaccharides joined together.
Have a sweet taste and are soluble in water
Polysaccharides
complex carbohydrates formed when
repeated dehydration synthesis reactions add additional
mono or disaccharides.
Can be straight chain or highly branched in structure.
starches
large polysaccharides formed from glucose
molecules.
lipids
contain C, H, and O. C:H is near 1:2.
Contain much less O than carbohydrates.
Most lipids are insoluble in water.
Lipids form essential structural
components of all cells.
Lipid deposits in the body are
important sources of energy
reserves.
Lipids provide (on average) twice as
much energy as carbohydrates do.
fatty acids
long C chains with H atoms
attached.
A carboxyl group (-COOH) is
always attached to one end
of a fatty acid.
saturated or unsaturated fatty acids
- in saturated each C atom in tail has
four single covalent bonds. - in unsaturated one or more of the
single bonds is replaced by a double
covalent bond.
steroids
large lipid molecules with a distinctive four-ring C
structure.
proteins
The most abundant (and most
important) organic molecules in
the body.
Proteins account for ~20% of
total body weight.
Contain C, H, O, and N
Proteins are made up of Amino
Acids.
7 functions of proteins
- Support (structural proteins)
- Movement (contractile proteins)
- Transport (transport proteins)
- Buffering pH
- Metabolic Regulation (enzymes)
- Coordination & Control (hormones)
- Defense (antibodies, clotting
proteins)
protein primary structure
The primary structure of proteins is the sequence of
amino acids along the length of a single polypeptide.
Primary structure is determined by peptide bonds
protein secondary structure
The secondary structure is the result of hydrogen
bonding between atoms at different parts of the polypeptide
chain. Secondary structure can be either an alpha helix or
beta sheet.
protein tertiary structure (3)
The tertiary structure is the complex coiling/folding
that gives the protein its final 3D shape
protein quatenary structure
The quaternary structure is the interaction among
individual polypeptides to form a protein complex.
A single polypeptide (left) interacts with other polypeptides to form a large
protein molecule (right)
Tertiary Structure
Quaternary Structure
nucleic acids
large organic molecules made of C, H, O, N, and P
-Nucleic acids consist of one or two long chains of
nucleotides bound together by dehydration synthesis.
Purines = double-ringed
Pyrimidines = single-ringed
DNA
consists
of a pair of nucleotide chains held
together by hydrogen bonds.
Rna
consists of a
single chain of nucleotides.
Shape of RNA depends on the order of
nucleotides in RNA chain and the
interactions among them
