Test 1 Flashcards
Common to all living things
1) cells
2) biological molecules: carbs, lipids, proteins, nucleic acid
3) metabolism
4) homeostasis
5) respond to stimuli
6) exchange with environment
biological phenomena that is physical
gravity, friction, pressure
biological phenomena that is chemical
diffusion, osmosis, digestion
why is stomach considered an organ and not a tissue? describe one aspect of stomach anatomy, describe one aspect of stomach physiology
an organ is made up of two or more tissues and the stomach has more than one tissue, therefore it is an organ.
stomach anatomy: cardia, connected to the esophagus
stomach physiology: relaxation and contraction of the stomach muscles that help mix up and break down food for digestion.
levels of organization for the human body. where is dividing line between living and nonliving?
chemical - cellular - tissue - organ - organ system - organismal level. the line is between chemical and cellular
general characteristics of model organisms
used for research to understand natural world
easy to house, breed, handle, sacrifice
what % of lean adult body is made up of water?
60-70%
what are the substances that commonly occur in body fluids?
Mostly water, but vary in composition, different concentration of solutes: Na+, glucose, O2, albumin, etc.
saliva is a body fluid. is it an intracellular or extracellular fluid? what is the solvent? what are some solutes?
extracellular.
solvents: 98% water
solute: also contains important solutes such as electrolytes, mucus, and enzymes.
what are the body’s 3 major fluid compartments?
Plasma (ECF) - 7%
Interstitial (ECF) - 26%
Intracellular (ICF) - 67%
what compartment does most body fluid occur?
intracellular - 67%
what barrier separates plasma from interstitial fluid?
blood vessel wall
What is the barrier that separates interstitial fluid from intracellular fluid?
plasma membrane
describe homeostasis and map out a home heating system, labeling the main components of a negative feedback system
Homeostasis is maintaining a relatively stable internal environment, despite fluctuations in external environment
Home heating system:
Receptor: thermometer in thermostat is monitoring the temperature in environment. Detects a drop in temperature and sends a message to the thermostat: Afferent pathway
Control center: thermostat has a set point of 20 degrees. Receives the message that temperature is below this and decides to turn on heat.
Effector: heater turned on, temperature in room begins to increase.
What is a receptor?
cell or set of cells that are monitoring a variable. Sends information to
Control Center
has established set point, and knows what conditions should be. Control center receives the information, combines info, analyzes and determines course of action.
Effector
able to actually change the physiological variable. receives information from CC, and when it engages it can change the physiological variable
Map out the body’s heating or cooling system and its feedback system
Receptors: thermoreceptors in skin and hypothalamus detect a drop in body temperature. sends information to control center
Control center: neurosecretory cells in hypothalamus and thyrotropes in pituitary gland receive messages from the receptors that there is a drop in BT. sends nerve impulses to skeletal muscles to start shivering
Effectors: skeletal muscles contract, body shivers and warms up
negative feedback system vs. positive feedback system
negative feedback: works to reverse the change
positive feedback: reinforces the change
example of positive feedback system
childbirth:
Contractions of wall of uterus force the baby’s head or body into the cervix → stretches cervix → receptors: stretch-sensitive cells in cervix send nerve impulses → control center: brain interprets input and releases oxytocin → effectors: muscles in wall of uterus contract more forcefully → baby’s body stretches cervix more → interruption of cycle, birth of baby decreases stretching, thus breaking the positive feedback cycle.
Example of disease and how
diabetes is an example of a disruption to homeostasis
set point: normal blood glucose level
eat breakfast and blood sugar goes up, receptors: beta cells in pancreas monitor and detect blood sugar has gone up. When they detect this, they secrete insulin into your blood. In response to insulin, cells start taking in glucose. As glucose moves into cells, it comes into blood and blood glucose goes down.
In diabetes, the body is unable to adequately regulate the amount of glucose in blood.
what is acclimatization?
physiological changes following repeated exposure to a particular environmental circumstance
Ex: people living at a higher altitude have higher density of hematocrits
what is circadian rhythm?
internal body clock
What four elements make up the 96% of the body and what are their symbols?
C Carbon
H Hydrogen
O Oxygen
N Nitrogen
What is the basic structure of an atom? Where do each of the following occur and what charge does each carry?
Atoms all have atomic nucleus, which is made up of protons (+) and neutrons (neutral)
Electrons occur outside of the nucleus and are negative.
What is the defining characteristic of any given type of atom?
how many protons are in its nucleus
A particular atom of chlorine (Cl) contains 17 protons, 18 neutrons, and 18 electrons. What is its atomic number? Does the atom carry a charge, overall (is it an ion)? If so, is it a cation or an anion?
atomic number = 17
Since it has “gained” an electron, it makes it a negative charge, which is anion
Potassium’s atomic number is 19. How many electrons are present in a potassium ion that carries a single positive charge (K+)?
18
cation vs. anion
cation = + becomes positive by gaining electrons anion = - becomes negative by losing electrons
polar covalent bond vs. non-polar covalent bond
polar: electrons are shared unequally between two atoms. have opposite charges at either end. This gives rise to one end of the bond that is slightly negative and the other end slightly positive.
non polar: electrons are shared equally between two atoms. This gives rise to an even distribution across the board.
What are the weak forces of attraction between group of neighboring water molecules?
hydrogen bonds
In one molecule of water, what is the chemical bond connecting hydrogen and oxygen?
polar covalent bond
Olive oil consists mostly of triglycerides. What happens when olive oil is added to water? Why?
The polar attraction of water molecules squeezes the non polar molecules out of the water phase and oil floats to the top
What is the percent (%) concentration of a solution in which 5 grams of glucose were added to water, to make a total volume of 150mL?
percentage = mass of solute/volume of soltion 5/150 = .03%
What is the molar (M) concentration of a solution in which 2 moles of glucose have been dissolved in 2.5 liters of water?
2/2.5 = .08
Bases have what ions and acids have what ions?
All bases have OH- ions while acids have H+ ions.
Adding NaOH to a solution would cause the pH to increase —-> base
Blood PH is?
7.35-7.45, slightly alkaline
What do the laws of conservation and mass state?
Energy can neither be created or destroyed. All of the energy present propane’s reactants, can also be accounted for in the products. It’s either given off or liberated by the reaction, or its stored in the products and the reactions. Mass is conserved, energy is conserved. Biology has to follow these laws.
monomer subunit of a protein is?
amino acid
monomer subunit of glycogen is?
polymer subunit is?
monosaccharide
polysaccharide
4 classes of biological molecules are?
carbs
lipds
proteins
nucleic acid
hydrophilic and examples
water loving
Na+, glucose
hydrophobic and examples
water fearing
lipids, triglycerides
amphipathic and examples
loving both
phospholipds, transmembrane proteins