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112 Cards in this Set

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why is a hydroxide ion negatively charged?
bc it has gained an electron from the hydrogen atom
pure water contains _____ concentrations of hydrogen ions and hyrodixde ions.
equal
if the concentration of H+ exceeds the concentration of OH-, the solution is _____
acidic
a substance that releases hydrogen ions when it is dissolved in water.
acid
what happens when HCl is added to pure water?
almost all of the HCl molecules separate into H+ and Cl-.
A substance that combines with hydrogen ions, reducing their number.
base
the degree of acidity is expressed on the _____.
ph scale
what is neutrality on the ph scale?
7, equal numbers of H+ and OH-
acids have a ph ____ 7.
below
bases have a ph ____7.
above
small increases or decreases in ph may cause....
drastic changes in both the structure and function of biological molecules, leading to the death of cells or entire organisms.
compound that tends to maintain a solution at a constant ph by accepting or releasing H+ in response to small changes in H+ concentration.
buffer
what happens if blood becomes too acidic?
bicarbonate accepts H+ to form carbonic acid
what happens if blood becomes too basic?
carbonic acid liberates hydrogen ions, which combine w/ the excess hydroxide ions, forming water.
why are subfreezing temp. within the body usually lethal?
spearlike ice crystles can rupture cells
temperature reflects the speed of what?
molecules
the ____ the temperature, the ____ the molecule's average speed.
higher, greater
true/false
it requires more energy to heat water than it does to heat most other substances
true
the energy required to heat a gram of a substance by 1 celsius is called its....
specific heat
heat required to vaporize water is called...
heat of vaporization
true/false
ice is more dense than liquid water?
false- ice is less dense
what are the 3 domains of living organisms?
1. bacteria
2. archaea
3. eukarya
no nucleus, small simple organisms, prokaryotic organisms
bacteria
extreme ophiles-->live in extreme conditions. single, simple cells
archaea
inside the cell is a nucleus, includes membrane organelles, much bigger than prokaryotic cells.
eukarya
what are the major subdivisions of eukarya?
animalia, plantae, protists, and fungi
use photosynthesis to make their own energy (plants)
autotrophs
eat organisms for energy (humans)
heterotrophs
the unifying theory of biology
evolution
the scientific theory derived from what..?
observation and experiments
what is the evolutionary process?
1. genetic variation/ competition among variants
2. not all survive
3. adaptive characteristics inherited
a bacterial cell in the human body with a genetic variation that allows it to survive when the person takes antibiotics is an example of what..?
natural selection
parts of molecules, the basic structural unit of matter (the smallest pieces of stuff)
atom
positive charge
proton
negative charge
electron
no charge
neutron
an element is defined by the number of ____?
protons
the number of protons in a molecule tells us what?
the atomic number
what is the atomic mass?
number of protons + number of neutrons
what is the building up principle?
electrons fill the shell closest to the nucleus, then begin to occupy the next shell
how many electrons can the first shell hold?
2
how many electrons can the 2nd and 3rd shell fill?
8
ionic bonding is an attraction between...
ions
sodium has 1 electron in its outer shell, chlorine has 7, sodium can lose 1 electron to make chlorine's outershell full. what type of bonding is this?
ionic
makes up arthropod exoskeletons and fungus cell walls. polymer with glucose subunits and N-containing functional groups
chitin
what are lipids?
1. fats, oils, and waxes
2. phospholipids
3. steroids
what are the 2 characterisitcs of lipids?
1. large regions with mostly C and H; nonpolar
2. hydrophobic; insoluble in water
is the head of a phospholipid polar or non polar?
polar
is the tail of a phospholipid polar or non polar?
non polar
true/false
heads of phospholipids are hydrophobic?
false- they are hydrophilic
hydrophobic membrane core
where 2 phospholipid tails meet (tails hate water, heads love water)
what are phospholipids made of?
1 glycerol, 2 fatty acids, and 1 polar group
what hormones are steroids?
estrogen and testosterone
in a biological membrane, the phospholipds are arranged with the fatty acid chains facing the interior of the membrane. as a result, the interior of the membrane is....
hydrophobic
amino acid polymers
protein
proteins play many roles in cells...what are they?
enzymes, hormones, structure, defense
what are amino acids made of?
1 amino group, 1 carboxyl group, 1 "R" group
true/false
amino acids are molecular subunits of proteins
true
amino acids are joined by peptide bonds to form...?
polypeptides
different sequence of amino acids make...
different proteins
what are the levels of protein structure?
primary: sequence
secondary: coiling
tertiary: bending
quarternary: 2 or more chains together
you have identified a protein that is unable to form disulfide bridges. this would affect which of the following?
tertiary structure of protein
nucleotide polymers that function in genetics and cell control
nuceleic acids
ATP is a..?
energy carrier
what are nucelotides made of?
5 carbon sugar, phosphate, and N-containing base
glucose is to starch as _____ is to _____.
amino acid; protein
what are 3 memrane functions?
1. selectively isolates inside of the cell from the outside
2. regulates exchange of substances in and out of the cell
3. facilitates communication with other cells
what are the membrane proteins?
1. transport proteins
2. recognition proteins
regulates movement through membrane
transport proteins
what are 3 types of transport proteins?
1. channel proteins
2. carrier proteins
3. receptor proteins
proteins that punch a hole through membrane
channel proteins
trigger cellular response when specific molecules attach
receptor proteins
ID tags and attachment sites
recognition proteins
what is a type of recognition protein?
glycoprotein
movement down concentration gradient, no energy required
passive transport
water moves through differentially permeable membrane
osmosis
molecules move from area of high concentration to area of low concentration; down concentration gradient. after time concentrations become equal
diffusion
what are the 3 effects of osmosis?
istonic, hypertonic, hypotonic
"cell eating", cell englufs large particles
phagocytosis
"cell drinking", cell englufs extracellular fluid
pinocytosis
the cytoplasm of a certain cell, such as a neuron, already has a high concentration of K+ ions. How can K+ ions enter the cell?
active transport
strengthen attachment between cells and holds tissues together
desmosomes
prevent leakage between cells
tight junctions
cell to cell channels connecting adjacent cells. only in animals
gap junctions
channels through plant cell walls connecting adjacent cells
plasmodesmata
the electrical signal for a muscle to contract passes rapidly from one muscle cell to the next way of ____.
gap junctions
covalent bond
when an atom with a partially full shell becomes stable by sharing electrons with another atom
solutions that have a higher concentration of dissolved particles than does a cell's cytoplasm, and thus causes water to leave the cell by osmosis
hypertonic
concentration of water inside the cell is the same as concentration on the outside of cell, so there is no tendency for water to enter or leave the cell
isotonic
solutions that have a lower concentration of dissolved particles than a cell's cytoplasm, and thus cause water to enter the cell by osmosis
hypotonic
what happens when red blood cells are put into pure water (hypotonic solution)?
they will swell and eventually burst
what happens when red blood cells are put into a hypertonic solution?
cells will shrivel up until the concentrations of water inside and outside the cell become equal
outer surfaces of the cells of bacteria, plants, fungi, and some protists are covered with non living, typically stiff coatings called....
cell walls
cell walls are produced by....
the cells they surround
what do plant cells secrete though their plasma membrane, forming the primary cell wall?
cellulose
a layer made of primarily pectin, that joins the primary cell walls of adjacent cells
middle lamella
what does pectin solidify?
jelly
the structure that governs the interactions that occur between a cell and its external environment is the...
plasma membrane
acts as a gate keeper, allowing only specific substances in or out and passing chemical messages from the external environment to the cell's interior
plasma membrane
_____ form compartments in which specialized biochemical activities can occure
internal membranes
____ are responsible for the isolating function of membranes
lipids
____ regulate the exhange of substances and communication with the environment
proteins
the head of a phospholipid is?
polar and hydrophilic
a phospholipid is?
non polar and hydrophobic
consists of all a cell's internal contents (including all the organelles except the nucleus, in eukaryotes), mostly made of water
cytoplasm
most biological molecules, including salts, amino acids, and sugars, are polar and water soluble, and so are _____.
hydrophilic
in most animal cells, the phospholipid bilayer of membranes also contains ______.
cholesterol
what are some ways that cholesterol affects membrane structure and function?
1. it makes the bilayer stronger
2. more flexible but less fluid
3. less permeable to water soluble substances such as ions and monosaccharides
glycoproteins
proteins that are embedded within or attached to the surface of a membrane's phospholipid bilayer
regulates the movement of hydrophilic molecules through the plasma membrane
transport proteins
form pores or channels that allow small water-soluble molecules to pass through the membrane. specific to potassium, sodium, and calcium
channel proteins
have binding sites that can temporarily attach to specific molecules on one side of the membrane
carrier proteins