BIO 121 Exam 1

True or False: nothing in science is proven

True

Theory

well substained explanation of something in the natural world that can incorporate facts, laws, hypothesises etc

Gravitational Theory

gravity is factual, there is a vast body of knowledge that explains the facts of gravity

facts, inferences, laws, tested hypothesis

Evolutionary theory

facts. evolution itself is factual. inferences, laws

evolution accounts for the unity and diversity of life

emergent properties

new properties emerge at each level in biological hierarchy

result from arrangement of parts in an ecosystem/community

number of protons determines:

what chemical element it is

isotopes

same element, different number of neutrons

valence shells

determine chemical properties

lose, gain, or share to fill valence shell

how many electrons are needed to fill a valence shell?

8

except H and He (2)

silicon dioxide

sand, glass

atoms are joined by chemical bonds to form:

compounds

chemical formula

gives type and relative number of atoms in sequence

covalent bonds

outer shells of atoms have joined. strong and stable. atoms share valence electrons

Nonpolar

if electrons are shared equally

polar

if electrons are not shared equally (H2O)

if one element is more electronegative than the other

ionic bonds

form between positive (cations) and negative (anions)

strong w/o presence of water but weak in aqueous solution (because water has + and - charges)

hydrogen bonds

relatively weak. form when hyd. atom w/ partial positive is attracted to atom w/ partial negative

4 main classes of biological molecules

proteins

nucleic acids

carbohydrates

lipids

Monomer of proteins

amino acids

what do proteins do

enzymes- catalyze chemical reactions

structural/transport proteins help w/ cells

monomer of nucleic acids

nucleotides

what do nucleic acids do

code for genetic info

monomer of carbohydrates

monosaccharides

what do carbs do

storage for glucose

monomer of lipids

fatty acids and glycerol

what do lipids do

form cell membranes

carbon atoms

form up to four covalent bonds

single, double, or triple bonds

straight, branched, or rings

bond with many different elements

structural isomers

different covalent arrangements

ethanol C2H60

geometric isomers

different spatial arrangements

enatiomers

mirror images

Polymers

long chains of monomers

often linked via condensation reactions

Macromolecules

large polymers

(polysaccharides, protein, DNA)

often broken down by hydrolysis

water exhibits _________ because it forms hydrogen bonds with itself

cohesion

water molecules exhibit __________ by hydrogen bonding to substances with ionic or polar regions

adhesion

water has a high s____________ h________

specific heat

hydrogen bonds must break to raise water temperature

specific heat of water helps:

organisms maintain constant internal temperature

stabilize the temperature of large bodies of water (oceans). this greatly affects climate

water has a high heat of _____________

vaporization.

hydrogen bonds must break for molecules to enter vapor phase

molecules carry heat, causing evaporative cooling

hydrogen bonds between water molecules make ice:

less dense than liquid water

acids

proton doners (H+)

dissociate in solution to yield H+ and an anion

bases

proton acceptors

dissociate in solution to yield hydroxide ions (OH-)

Carbohydrates

one carbon, two hydrogen one oxygen

composed of sugar subunits!!!! (monosaccarides) which can be linked into polysaccarides

monosaccharides

polysaccharides

disaccharides

Storage polysaccharides

starch in plants, glycogen in animals

Structural polysaccharides

cellulose, cell walls of plants

chitin, cell walls of fungi and exoskeletons

Lipids

fats/oils

glycerol and three fatty acids

saturated or unsaturated

triacylglycerol

main storage fat

Phospholipids

structure: glycerol, 2 fatty acids, phosphate

function: cell membrane component

water attracts to hydrophilic heads

steroids

carbon atoms arranged in 4 rings

cholesterol, bile salts, some hormones

Proteins

polypeptides

20 amino acids

long linear polymers joined by peptide bonds

ex: enzymes, proteins (structural, storage, transport, regulatory, motile, protective)

What aspect of a protein determines its function?

3-D shape, conformation, quaternary/tertiary structure

(((shape)))

Primary strucuture

linear sequence of amino acids

Secondary

regular conformation, fold up and loop

hydrogen bonds between amino acids

Tertiary

overall shape of polypeptide chain

chemical interactions of side chain

Quaternary

tertiary chains combined

Nucleic Acids

made of nucleotides

nitrogenous base (2 ring purine or 1 ring pyrimidine), phosphate group, sugar (ribose or deoxyribose)

Pyrimidines

cytosine (DNA and RNA), thymine (DNA only), uracil (RNA only)

Purines

Adenine and Guanine

ATP

adenosine triphosphate

essential in energy metabolism

NAD+

electron acceptor in biological oxidation and reduction reactions

DNA and RNA

long chains of nucleotides

store and transfer information

-sequence of amino acids in proteins

-structure and function of an organism

Diffusion

net movement of substances down their concentration gradient

from high concentration to low concentration

does not use direct metabolic energy!!!!

phospholipid molecules

amphipathic

hydrophobic fatty acid tail, hydrophilic head

Plasma membrane

fluid!!!! (fluid mosaic model)

physically separates interior from exterior of cell

receives info about changes in environment

regulates passage of materials in and out of cell

communicates with other cells

forms compartments to allow separate functions

participates in biochemical reactions

biological membranes

selectively permeable membranes that help maintain homeostasis in the cell

integral membrane/transmembrane proteins

embedded in bilayer

extend completely thru membranes

peripheral protiens

at surface of bilayer

bound to exposed integral proteins

semi-permeable membranes

allows passage of some substances

Osmosis

type of diffusion

H2O molecules pass through the semi-p membrane from higher to lower concentration

Correct order for hierarchy of biological organization from least to most complex

molecule, organelle, cell, tissue, organ, organ system, organism, population, community, ecosystem

No amino acid molecule by itself can speed up or catalyze reactions between other molecules; however, when amino acids are joined together to make a protein with catalytic properties, the new structure (enzymatic protein) can speed up the rate of a specific chemical reaction. What does this illustrate?

emergent properties

What happens to chemical nutrients in the environment?

They are recycled within the ecosystem, being constantly renewed.

Which taxonomic domain includes multicellular photosynthetic organisms?

Eukarya

In animal populations, DDT causes:

birth defects

An organ, such as the liver, is composed of:

tissues

What are the two main types of cells?

Prokaryotic and Eukaryotic

Deductive reasoning

conclusion is based on the concordance of multiple premises that are generally assumed to be true

Ex: You learned in elementary school that as temperature drops, liquids change into solid form. You are given an unfamiliar liquid and hypothesize that it will become solid if you put it in the freezer.

Atoms with similar electronegativities form

nonpolar covalent bonds

adhesion

water molecules sticking to other things

(plant cell walls, side of a beaker)

cohesion

water molecules sticking to each other

(droplet on table)

an acid is a substance that

increases the hydrogen ion concentration of an aqueous solution

buffer

resists change in pH by accepting hydrogen ions when acids are added to the solution and donating hydrogen ions when bases are added.

van der waals

forms between atoms of equal electronegativity

most organic compounds contain

carbon and hydrogen

(hydrocarbons)

amino group

NH2

(base)

phosphate group

PO4

major role in energy transfer

hydroxyl group

OH

characteristic of alcohol

carboxyl group

COOH

acid

carbonyl group

C double bonded to O

keytone

methyl group

carbon bonded to 3 hydrogen

animals store energy in the form of

glycogen

____________ is the disaccharide formed when two glucose molecules are linked by dehydration synthesis

maltose

endocytosis

forms vesicles from inward folding of plasma membrane

decreases surface area of membrane

exocytosis

secretes large molecules out of the cell

requires fusion of vesicles with plasma membrane

increases surface area of membrane

phagocytosis

engulfing of large particles (solids)

pinocytosis

cell engulfing fluids

"cell drinking"

receptor-mediated cytosis

formation of coated molecule brought inside, coat removed, binds with vesicle inside

Fimbriae

enable bacteria to stick to a surface

central vacuole

storage

smooth ER

lipid synthesis

calcium ion storage

poison detox

rough ER

has ribosomes

protein synthesis

golgi apparatus

protein modification and sorting

cisternal maturation