Biology first exam

What is science

A way of thinking

What can science NOT do

determine morally right from wrong, address god, explain feelings

5 steps of scientific method

observations, hypothesis, testable prediction, conduct experiment, conclusion

Observations are

description, measurement, 5 senses

Hypothesis

Informed logical and plausible explanation, statement, testable

Prediction

IF and THEN statement

How to conduct experiment

repeatable manipulation of one or more aspects of natural world

Elements of an experiment

control group, independent and dependent variables, treatment group, double blind, randomized

scientific literacy

understanding basics of science and scientific process

Correlation…

does not equal causation

Independent variable

manipulate variable from one group to another

Dependent Variable

responds to changes in independent variable

Treatment group

experimental group, same conditions as control, manipulated

Organisms are composed of

matter

chemical reactions occur to

move and grow

4 elements make up living things

hydrogen, carbon, nitrogen, oxygen

Atom

Smallest element that has characteristic

atoms are broken into

subatomic particles

what are the 3 subatomic particles

protons, neutrons, and electrons

How many electrons are in 1st shell and 2nd and 3rd shell

2, 8

What happens with nuclei during chemical reaction

2 atoms do not come close together

Knowing how many electrons an atom has helps to

see how they interact

Chemical bond

attractive force that holds atoms together and link to molecule

What are types of chemical bonds between atoms

covalent polar and nonpolar and ionic

Electronegativity

atoms attraction for electrons in covalent bond

what does electronegativity determine

polar or nonpolar

The more electronegative…

stronger pulls electron toward itself

How to know by electronegativity if atoms are polar

if there is a greater than .4 difference

What would classify as equal sharing in a covalent bond?

.4 or less difference of electronegativity between the two atoms

What would classify as unequal sharing in a covalent bond?

greater than .4 difference in electronegativity

In covalent bonds, more time near oxygen means…

slightly negative charge

In covalent bonds, less time near hydrogen means

slightly positive charge

What type of molecule is water

polar covalent

Ionic bonds are when…

more than 1.7 difference in electronegativity

Ionic bonds result in

complete transfer to highly electronegative atoms

In ionic bonds, an atom that loses electron becomes

positively charged

In ionic bonds, an atom that gains electron becomes

negatively charged

A slight positive charge on hydrogen atom will attract…

negative charge on oxygen of neighboring water molecule

What gives water unique properties

hydrogen bonds that hold the water molecules together

cohesion

attraction between like molecules

adhesion

attraction between unlike molecules

What keeps water together

hydrogen bonds

What allows water to adhere to the surface

polar components

Surface tension

cohesive force caused by attraction between molecules at surface of liquid

Are molecules at surface weaker or stronger and why?

stronger bc of hydrogen bonding

What happens as water freezes

forms open crystal structure

Is ice more or less dense than liquid

less dense

Why is ice being less dense better

because it forms insulating blanket at top of body allowing animals to live underneath

Does water have high or low specific heat

high

High specific heat

amount of energy needed to raise temp of 1g of substance by 1C

What is the temperature of a substance measure

how quickly the molecules are moving

Hydrophillic

water loving

hydrophobic

water fearing

hydrophobic characteristics

uncharged, non polar, cant dissolve in water

How hydrophilic works

ions and polar molecules stay in solution due to their interactions with waters partial charges

What results when highly electronegative oxygen keeps electron

hydrogen ion

pH

negative logarithm of H+ concentration

Acid solutions have what kind of pH

low

Neutral solutions have pH of…

7

Neutral solutions have what ions

equal amt of OH- ions than H+ ions

Acid solutions have what ions

high H+

Basic solutions have what kind of pH

high

Basic solutions have what kind of ions

low H+ and more OH- than H+

organic molecule

molecule that contains carbon bonded to other elements linked in a chain or ring

almost all molecules found in organisms contain what element

carbon

What are the four classes of macromolecules

carbohydrates, proteins, nucleic acid, lipids

All macromolecules aside from lipids are

polymers

Polymer

large macromolecules composed of many monomers linked together

Dehydration reactions do what

join monomers into polymers

does H2O go in or out during dehydr

Does H2O go in or out during hydrolysis

in

Hydrolysis

break polymers into monomers

what function group is this

hydroxyl

what functional group is this

amino

what functional group is this

carboxyl

what functional group is this

phosphate

where are functional groups found

mono, di, and polysaccharides

monosaccharides are

one sugar monomers

disaccharides are

two sugars

polysaccharides are

many sugar polymers

Complex carbs are

long chains of glucose

Example of complex carb

polysaccharide

Examples of polysaccharides

cellulose, starch, glycogen

Cellulose

structure of plant cell walls, very solid

starch

energy storage in plants

starch has no

hydrogen bonds

How are starch polysaccharides assembled

made up of glucose

what does glucose molecule linkage allow for

branching and high solubility in water

How are glycogen polysaccharides assembled

with hydroxyl groups and molecules only face right side up

Are glycogen and starch polar or nonpolar and why

polar bc of hydroxal groups

Structure of cellulose and why

straight rodlike molecules held by hydrogen bonds and insoluble in water

Proteins are (3 things)

complex, highly versatile, polymers of amino acids

What do proteins do

carry out crucial bodily functions

monomer is an

amino acid

monomers have what 2 functional groups and do what in water

amino and carboxyl, ionize

ionization of water helps amino acid

stay dissolved and be highly reactive

How do amino acids differ

R groups (side chains)

What do the side chains traits help us know

how strands will interact with others

what characteristic and what do they attract

acidic, positive

what characteristic and what do they attract

basic, negative