fall midterm Flashcards
what are the 7 characteristics we use to define life?
order, process energy & metabolize, growth & development, reproduction, respond to environment, homeostasis/ regulation, and adaptation/ acclimation
how do we maintain order?
everything that is alive is organized on the cellular principal that is organisms are composed of one or more cells
what is the FIRST law of thermodynamics?
law of energy conservation states energy cannot be created or destroyed
what is the SECOND law of thermodynamics?
the entropy law states all things tend towards maximum entropy or randomness/disorganization
growth & development
growth increases mass, cell size or how many cells there are.
development involves differentiation
reproduction
living things must reproduce to sustain spices. reproduction can include repro of new cells or of a new life
responsiveness
the ability to respond is fundimental to homeostasis. this can be an active response or passive response
what is homeostasis/ regulation
homeostasis is the ability for the body to maintain stability while going through changing conditions
what is adaptations and acclimation?
adaptations, long term change in genes to maintain survival
acclimations, short term responses to the environment like humans wearing coats in the winter to stay warm
what are ectotherms?
rely on the temperature of their surroundings for body heat
what is the biological organization?
atoms -> molecules -> organelles -> cell -> tissue -> organ -> organ sys -> organism -> population (group of species)-> community ( all species in the place) -> ecosystem (living & non) -> biosphere(earth)
what is the chemical level of organization?
atom -> molecule -> macromolecule
what is the first level of organization that life emerges?
cells
what is the flow of energy? what is this cycle called?
nature does not waste energy, so it uses the cycle of matter. inflow of light energy comes from the sun -> used producers (plants) -> to make chemical energy in food -> eaten by consumers (animals) -> creates outflow of heat
each step uses heat and energy, the energy goes into less useful forms each time it transitions
what evidence shows that all life is unified?
the universal usage of DNA to store genetic info. all life is made up of cells that contain this DNA and provides the cell with instructions on how to make proteins we need to survive and reproduce.
what creates diversity?
diversity of life arises from the differences in DNA sequences allowing us to all have different genes
what are the 3 domains of life?
-bacteria, diverse and wide spread
-archaea, similar to bacteria, found in hot and high pressure places
-eukarya, includes us and plants, has smaller kingdoms like protists (unicellular like algae and ameoba), plantae (producers), fungi (decomposers), and animalia ( consumers)
How does the theory of evolution describe both the unity and diversity of life? what are the two observations from Darwin?
-heritable variations, variety of traits you inherit from parents
-overproduction of offspring, populations produce more offspring than the environment can support, because of this the offspring that are able to adapt the most are going to survive
because of these observations we can see that throughout evolution all species change to be able to survive
what is natural selection?
natural selection is how life changes over time. species adapt to their environments to maintain life and overtime the offspring who cannot adapt will disappear and leave only the strongest to reproduce
what is a hypothesis?
a hypothesis is a testable explanation for observations based on data, ex: if flashlight batteries are dead then changing the batteries will make it work
what is a controlled experiment?
a controlled experiment is testing one variable at a time. this means changing only one factor to see the effects while others are kept constant.
what is the order of the scientific method?
-observation
-question
-hypothesis
-prediction
-test
how was mimicry helpful to non-poisonous King snakes in an environment where there were population overlaps with
coral snakes?
by mimicking the look of the poisonous snakes it allowed the non poisonous snakes to survive. Predators who live in areas with coral snakes have “learned” to avoid them and
so will also avoid a similarly coloured snake
what is the control group? what is the test group?
-the control group in the experiment that does not receive treatment
-the test group in the experiment receives the treatment
what is an atom?
smallest unit of matter
what is a molecule?
the covalent bonding of two or more atoms together (H2)
what is an element?
a substance that cannot be broken down into other substances by ordinary
chemical means
what is a compound?
the combination of two or more DIFFERENT elements (H2O)
what elements make up 96% of life?
H (hydrogen), C (carbon), N (nitrogen), and O (oxygen). in smaller amounts there is also S (sulfur) and P (phosphorus)
what are the 3 subatomic particles? charges, sizes? which one is responsible for defining the element? which one is responsible for reactivity?
-protons (+), found in nucleus, defines what the element is because no two elements have the same number of protons
-neutrons (=), found in nucleus
-electrons (-), found around the nucleus in orbitals or shells, smallest, determines reactivity of element by how full the valence shell is
what is atomic number?
the number of protons in the nucleus
what is atomic mass/weight?
the sum of protons and neutrons
what is an isotope?
an element that has more of less neutrons than it normally would but still has all of the same properties and reactivity
of the atom
what is a radioactive isotope?
an element is unstable (nucleus breaking down) and degrades gradually over time as it
emits radiation, we can quantify this and use it in medicine
how many electrons fit into the first shell? second? outer most?
2, 8, 8
how many electrons can fit on 1s orbital and 2s orbitals? how many in three 2p orbital?
each orbital can hold 2 electrons. a three 2p orbital can hold a total of 6 electrons because there is three orbitals together (makes flower shape)
how are electron shells and orbital related?
each electron shell consists of orbitals. the first shell has one, second has 4, and so on.
what do you call electrons in the outer shell?
valence electrons
What is a stable number of electrons in a valence shell?
8
what are the three types of chemical bonds?
-covalent, formed by the sharing of valence electrons between two atoms (nonpolar- share equally, polar- share non equally)
-ionic, formed when one atom gives
up an electron from an outer shell and the other atom adds the free electron to its
outer most shell, thereby holding the atoms together
-hydrogen, an attraction between two atoms that already participate in other chemical bonds that always include H
what is a double bond?
the sharing of two electrons between two atoms
What is electronegativity?
The ability to attract electrons from other atoms in a molecule
Do electrons closer to or further from the nucleus have a higher energy level?
further
what are polar bonds? why are they important to water?
there is an unequal sharing of the
electrons, the electrons spend more time orbiting one nucleus than the other.
in water, electrons are closer to O atom than H giving O slightly (-) charge and H slightly (+) charge making water polar. because water is polar, each water molecule attracts other water molecules because of the opposite charges between them, forming hydrogen bonds.
What are some of the unique properties of water because of this hydrogen bonding?
-high freezing (0) and boiling point (100)
-tensile strength due to cohesion (water moles sticking together) allows for resistance of molecules to being pulled apart (why bugs can walk on water)
-adhesion (water moles stick to other moles) allows for meniscus which is when water adheres to the sides of a container making a curved surface
-density, water is the only substance that is denser in liquid form than in solid form
what is a solution?
a liquid that consists of two or more substances
what is a solvent?
the dissolving agent
what is a solute
the agent being dissolved
what is the pH of water?
7
what is the concentration of H an OH in pure water?
1.0 x 10-7 moles (-7 is an exponent)
how much change is there between each number on the pH scale?
10 fold
what is acidic? what is basic?
-acidic, more H 0-6
-basic, less H 8-14
What is a buffer? what is the bicarbonate buffer system?
- a buffer is a solution that can convert or neutralize strong acids or bases into weak ones, resist drastic changes in pH
-bicarbonate buffer is a reversible equation, cardon dioxide (CO2) + water (H2O)= carbonic acid (H2CO3+), carbonic acid can donate an H if something is too acidic leaving us with a weak base called bicarbonate ion (HCO3-), because it is reversible, if solution is too basic, the bicarbonate ion will bind w the H (already has been donated by acidic part) to once again become acidic
what causes acid rain? what are the affects of acid rain?
-caused by man made sources like burning fossil fuels or natural sources like volcanoes. normal rain pH is 5.6 but acid rain is 4.2-4.4.
-it affects; -soil increased acidity dissolves nutrients that trees need to be healthy and makes it hard for them to intake water
-damages leaves, leach nutrience from soil and reduce soil fertility, and damages root systems
what causes ocean acidification? what/whos affected?
-caused by CO2 in the atmosphere coming to equilibrium with the CO2 that dissolves at the surface of water. this results in a decrease of pH in the oceans making them more acidic.
-coral reefs and marine animals with shells are affected. reducing pH and availability of calcium carbonates for making
shells results in impacts on the food web and decrease of biodiversity. decrease in calcification resulting from more
carbon dioxide in the water. if corals cannot make their skeleton quickly they dissipate.
what are independent, dependent, and codependent variables?
in- what you manipulate to explore experiment.
de-changes as result of independent variable manipulation.
co-when you change independent and expect a change in dependent but see another independent has changed as well.
Why is carbon the backbone of so many biologically relevant molecules?
carbon is the most abundent element in the universe. it easily breaks and forms bonds with oxygen and other carbons. carbon can form covalent bonds to as many as four different atoms making it a versatile building block
what is the keeling curve?
measurement of CO2 concentration yearly
how many valence elec does carbon have? how many covalent bonds does it make to fill valence shell?
-4 elec in valence shell
-4 bonds
What is the basic formula for a hydrocarbon?
hydrogen and carbon
methane=CH4
ethane=C2H6
formula for carbohydrates & functional groups
C and H2O
hydroxyl groups (OH) and carbonyl groups (C=O)
what are the functional groups?
hydroxyl (OH), carbonyl (C=O), carboxyl (COOH), amino group (NH2) and phasphate group (OPO3 squared (2)) ALL POLAR
methyl group (CH3) NON POLAR
formula for protein & functional groups
polymer made up of combos of the 20 diff amino acids.
functional groups of carboxyl and amino
formula for nucleic acid
ribose or deoxyribose sugar, phosphate group and nitrogen base
formula for lipids & functional groups
lipids are made up for glycerol and fatty acid chains
carboxyl and phosphate groups
what is an isomer? what are the three kinds?
an isomer is molecules with the same chemical formula, but a different arrangement of atoms
causing a different structure and function.
-structural-same formula, diff shape & arrangemtn of atoms
-geometric-always double bonded, diff location of functional groups, cis have functional groups on the same side of the molecule, while trans isomers have functional groups on opposite sides.
-Enantiomers – mirror images of each other
what is a monomer?
a molecule that serves as a building block for polymer
what is a polymer?
large molecule that consists of many monomers
what is a macromolecule?
large molecule such as protein
What chemical reaction is used make polymers?
dehydration synthesis
what is dehydration synthesis?
the formation of larger molecules
from smaller reactants by loss of a water molecule
what is a catalyst?
a substance that increases the rate of a reaction without being chemically changed
what is hydrolysis?
breaking polymers into smaller molecules by adding water back into them.
what is a monosaccharide?
single unit of sugar 1:2:1 ratio, C:H:O = CH2O, glucose
what is a polysaccharide?
many monos formed together through dehydration synth, starch
what is a disaccharide?
2 monos joined by dehydration synth
what is a starch?
polysaccharide found in plants. consists of glucose linked molecules
what is glycogen?
polsaccharide of glucose found in animals.
what is the difference between glucose and starch?
g is found in animals and is highly branched, found in muscle and liver cells
s is found in plants, can be unbranched or branched, stored as, amylose (straight chain) and
amylopectin (branched)
what is cellulose?
a polymer of glucose found in plant cell walls and cannot be broken down by animals (unlike starch)
what are peptide bonds?
amino acids are linked together between the carbon in carboxyl group and a nitrogen of amino group of another am acid forming a peptide bond.
what are the bases of DNA and RNA?
adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U) which is only in RNA
A&T, A&U(RNA), G&C
why are lipids not polymers?
they lack a monomer unit
what is a triglyceride made of?
one glycerol molecule and three fatty acid chains
what are the functions of fats?
long term energy storage, insulation, cushions organs, apart of cellular membranes
saturated v unsaturated fats
sat- no double bond, solid at room temp like butter or lard, saturated with hydrogen
unsat- double bond, liquid at room temp like oils
what are Fatty acids with several carbon-carbon double bonds?
polyunsaturated
Why do double bonds make fats more likely to be a liquid at room temperature
the double bond causes a bend in the chain which prevents the fatty acids from being able to pack tightly together
What is the name of the bond that forms between the carboxyl group of a fatty acid and the hydroxyl group of the glycerol molecule?
ester bond formed by dehydration synth
what is a condensation reaction?
a chemical reaction that joins monomers together with covalent bonds to create polymers
Why do phospholipids automatically form bilayers or micelles in aqueous solutions?
because phospholipids have both hydrophillic and hydrophobic components so when placed in water, they automatically protect the hydrophobic tails and allow the hydrophillic heads to interact with the water.
A type of lipid where the carbon skeleton contains 4 fused rings is called a
steroid, like cholesterol
How is cholesterol transported in the body?
they are transported by lipoproteins which are proteins combined with lipids
what is HDL and LDL? which is better?
HDL- high density lipoprotein, has more protein than fat and is better for you. reduces risk of heart attack and helps clear plaque from arteries.
LDL- low density lipoprotein, has more fat than protein, bad for you, sticks to artery walls forming
plaques which narrow the arteries and restrict blood flow causing high blood pressure
what is atherosclerosis? what is arteriosclerosis?
-plaque from excess cholesterol in the blood builds up in artery walls
-artery walls hardened by fibrous tissue and calcification
what causes heart attacks and strokes?
caused by the build up and hardening of the cholesterol in arteries. this causes the blood to pump harder due to narrow passages causing heart attacks and strokes
in 1855, Virchow added the biogenic law to cell theory…which states?
All living cells arise from pre-
existing cells
how did Louis Pasteurs experiment prove that life did not originate from non-
living matter?
Nutrient broths were heated and sterilized in a flask with a
straight neck and a curved neck. the flask with the straight neck saw bacteria growth imediatley, the s shaped flasks did not allow bacteria to enter therefor none grew. and when the s shaped neck was removed once again bacteria grew.
what did August Weissman add to cell theory?
in 1880 he added, cells living today can trace their ancestry back to ancient times. meaning cells have a common ancestor (bacteria)
what are the principals of cell theory?
All livings things are made of cells;
A cell is the smallest unit in a living thing; and
All cells come from other cells
larger cell = ____ ratio of S to V
less surface area to volume, though larger cells have more total surface area
what are prokayotic cells? eukaryotic?
pro- bacteria & archea, no mem bound organelles, small, reproduce through binary fission
euk- plants & animals, has true nucleus
similarities & differences between prokayotic and eukaryotic cells
similarities- have a cell membrane, one or more chromosomes carrying genes made of DNA, contain ribosomes, and both have cytoplasm
diff- pros have no nuclear membrane, the DNA is located in the nucleoid region, Smaller, and Some have a sticky outer coat that may or may not have surface projections
what is a vacuole? how do they differ in plants and animals?
Plant cells use their vacuoles for transport and storing nutrients, as well as balancing their water and are generally large
animals use vacuoles for storing waste
what is a contractile vacuole?
a contractile vacuole fills with water that continually enters the cell by osmosis from the environment and then contract,
expelling their contents to the exterior of the cell.
what are chloroplasts?
a double membrane organelle that contains it own DNA and ribosomes. convert solar (light) energy to chemical (sugar) energy
via photosynthesis for plants. they contain chlorophyl that give pigment to plants that is found in the stroma, stroma is a fluid in the innermembrane
what is endosymbiosis?
explains how mitochondria and chlorophyll came to be in eukaryotic cells. they are believed to have been undigested bacteria
What are the three components of the cytoskeleton?
microfilaments, intermediate filaments, and microtubules.
What motor protein is responsible for the movement of cilia and flagella?
axonemal dynein
how do phthalates affect sperm?
correlates with low sperm count and quality of sperm
what is primary ciliary dyskinesia?
an absence of dynein proteins, cilia of the lung and flagella of sperm cannot move, because the
microtubules cannot bend
What holds cells together in tissues? what are the tree types?
junctions:
-tight, bind cells together forming a leak-proof barrier between the cells
-anchoring, cells anchored together by cytoskeletal fibers, but allow small/liquid materials to pass between
-gap, protein lined pores connect through cytoplasm allowing ions to flow through. this junction is what allows heart cells to beat together because there is direct communication between cells
What functions do plant cell walls have? What are plasmodesmata
plasmodesmata are “holes” in the plant wall that allow to communication similar to gap junctions.
functions in skeletal support, absorption, transport and secretion of substances in plants
What organelle controls gene expression?
nucleus
Which organelles are involved in the manufacture, distribution, and breakdown of cellular materials
organelles in Endomembrane system
Which organelles produce energy in plants and animals?
mitochandria in plants and animals, and chrloroplasts in only plants
what organelles are in the endomembrane system? what do they do?
includes the nuclear envelope, both ERs, Golgi Apparatus, lysosomes, vacuoles, and the plasma membrane.
These
organelles work together in the synthesis, distribution, storage, and export of molecules
when is a covalent bond likely to be polar?
when atoms with different electronegativities share electrons in a covalent bond.
what is a cation? anion?
cation loses an electron making it positively charged.
anion gains an electron making it negatively charged
what holds secondary structure together? tertiary?
hydrogen bonds
interactions between R groups
what are the structures of protein?
-primary, order that am acids appear in the sequence
-secondary, alpha helix or beta pleated sheet
-tertiary, 3D shape, hydrophillic parts go outwards and hydrophobic goes inwards
-quaternary, multiple proteins together like hemoglobin, not every protein does this
What happens when a protein becomes denatured?
the secondary and tertiary structures get destroyed and only the primary structure is retained, caused by changes in pH or temp
What are some of the functions of proteins?
enzymes, transport molecules across membrane, defensive antibodies, and signals
what are the following groups; OH, COOH, C=O, NH2, OPO3-2, and CH3?
OH is hydroxyl
COOH is carboxyl
C=O is carbonyl
NH2 is amino
OPO is phosphate
CH3 is methyl
what is the monomer for nucleic acid?
nucleotides joined by dehydration synth
what nitrogen bases are pyrimidines?
cytosine, thymine, and uracil
what nitrogen bases are purine?
adenine and guanine
what bonds hold nitrogen bases together?
hydrogen bonds
what shape does a micelle bilayer form?
circle
what is the surface area of a cell? volume?
how the cell interacts with environment
internal cell
how do you get the surface area of a WHOLE cell?
if two sides are 30 microns but a cube has 6 sides…
30x30=900. 900x6= 5,400 microns is the surface area
how do you get the volume of a cell?
multiply 3 times because its a 3D shape…
30x30x30= 27,000 microns is the volume
how do you get the ratio of surface area to volume of a whole cell?
surface area / volume = ratio
5,400 / 27,000 = .2
how do you get the surface area of a single cube? (27 fit into a large one)
27 cubes fit in the large one and they all have 6 sides…
27x6= 162
10x10=100
162 x 100 = 16,200
what are peroxisomes?
carrying out oxidative reactions of fatty acids and generates hydrogen peroxide
what are the folds in the mitos matrix called? what is the space between double membranes called?
christase
intermembrane space
what are thylakoids?
stacked membrane in chloroplasts located in the stroma. the stacks are called granum
what are microfilaments, intermediate filaments, and microtubules made of?
microfill- actin protein as a solid rod shape thats twisted
inter- fibrous proteins coiled together
microtub- tubulin proteins forming a hollow tube
what are microtubules?
help to maintain cells shape, and with motor proteins act as tracts for organelles to move across
