TAMU BIOL111 - Exam 1 (chapters 1, 2, and 3 )

science

knowledge that covers general truths or the operation of general laws especially when acquired and tested by the scientific method

basic science

science that seeks to expand knowledge and understanding regardless of the short term application of that knowledge

applied science

form of science that aims to solve real world problems

discovery (descriptive) science

form of science that aims to observe, explore, and investigate

hypothesis based science

form of science that begins with a specific question and potential testable answers

inductive reasoning

form of logical thinking that uses related observations to arrive at a general conclusion

hypothesis

a tentative answer to a well framed question; an explanation on trial

deductive reasoning

form of logical thinking that uses a general inclusive statement to forecast specific results

scientific method

method of research with defined steps that include observation, formulation of hypothesis, testing, and confirming or falsifying the hypothesis

scientific theory

a carefully thought-out explanation for observations of the natural world that has been constructed using the scientific method and brings together many facts and hypotheses

theory

tested and confirmed explanation for observations or phenomena

generates new hypotheses

basic functions (properties) of life

1) order

2) sensitivity response to stimulus

3) reproduction

4) adaptation

5) growth and development

6) regulation/homeostasis

7) energy processing

8) evolution

levels of biological organization

1) organelles

2) cells

3) tissues

4) organs

5) organ system

5) organism/ population/ community

6) ecosystems

7) biospheres

hypothesis based science

form of science that begins with a specific question and potential testable answers

cell

the lowest level of organization that can perform all activities required for life

all cells:

are enclosed by a membrane

use DNA as their genetic information

2 major kinds of cells

prokaryotic + eukaryotic

organelles

small structure that exist within cells and carry out cellular functions

taxonomy

the branch of biology that names and classifies species into a hierarchical order

all life shares:

DNA, mRNA, tRNA

Ribosomes

Proteins of 20 amino acids

natural selection

Darwins second point about evolution: a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

phylogenetic tree

a branching diagram that represents a hypothesis about the evolutionary history of a group of organisms.

decent with modification

Darwin's principle about evolution that each living species has descended, with changes, from other species over time

matter

anything that has mass and takes up space

element

a pure substance made of only one kind of atom

atom

smallest unit of matter that still retains the properties of an element

subatomic particles

protons: + charge

neutrons: neutral

electrons: - charge

atomic number

the number of protons in the nucleus of an atom

atomic mass (mass number)

protons + neutrons

each has a mass close to 1 dalton (atomic mass unit = AMU)

isotope

differ in the number of neutrons in the atomic nucleus but have the same number of protons

radioisotopes

isotopes that have unstable nuclei and spontaneously give off particles and energy

molecules

groups of two or more atoms held together by chemical bonds

Bhor model

indicate how many electrons fill each principal shell

hydrophilic

has an affinity for water (water loving)

polar molecules which contain O-H or N-H polar covalent bonds

hydrophobic

does not have an affinity for water

noncharged and nonpolar molecules

4 emergent properties of water

1) high heat capacity

2) heat of vaporization

3) cohesive and adhesive properties

4) versatility as a solvent

specific heat

The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree celcius

heat is absorbed when hydrogen bond breaks

heat is released when hydrogen bonds form

kinetic energy

energy of motion

thermal energy

a measure of the total amount of kinetic energy due to molecular motion

temperature

measure of the average kinetic energy

heat of vaporization

quantity of heat a liquid must absorb for 1 gram to be converted from a liquid to a gas

evaporation

the transformation of a substance from a liquid to a gas

cohesion

bonding of a high percentage of the molecules to neighboring molecules

due to hydrogen bonding

surface tension

measure of how hard it is to break the surface of a liquid

related to cohesion

adhesion

attraction between water molecules and other molecules

mole

6.023 x 10²³ molecules

the mass of 1 mole of a substance is determined by its atomic or molecular mass

molarity

number of moles of a solute per liter (M=mole/L) of solution

acid

any substance that increases the hydrogen ion concentration of a solution

base

any substance that reduces the hydrogen ion concentration of a solution

pH

pH=-log[H+]

each pH unit represents a tenfold difference in H+ concentration

neutral solution: [H+] and [OH-] are both 10^-7 M

pH is low in an acid

pH is high in a base

buffers

substances that minimize changes in the concentration of hydrogen and hydroxide ions in a solution

consist of a weak acid base pair that reversibly combines with hydrogen ions

isomers

molecules that have the same chemical formula but differ in placement/arrangement of atoms or types of bond between atoms

structural isomers

have a different covalent arrangement of atoms

geometric isomers

have a different arrangement of atoms around a double bond

enantiomers

molecules that share chemical formula and bonds but differ in 3D placement of atoms; mirror images

6 functional groups

hydroxyl

carbonyl

carboxyl

amino

sulfhydryl

phosphate

methyl

functional groups

groups of atoms within a molecule that confer consistent specific properties to these molecules

4 major classes of macromolecules

carbohydrates

lipids

proteins

nucleic acids

organic molecules

all contain carbon

may also contain hydrogen, oxygen, nitrogen and some other minor elements

macromolecules

large molecules composed of smaller molecules

monomers

small unit that can join together with other small units to form polymers

polymers

molecules composed of many monomers; makes up macromolecules

dehydration synthesis

the creation of larger molecules from smaller monomers when a water molecule is released

linked by covalent bonding

form new bonds/ require energy

hydrolysis (dehydration reaction)

reaction that causes breakdown of larger molecules into smaller molecules by utilizing water

break bonds/ release energy

enzymes

biological molecules that catalyze or "speed up" reactions

carbohydrates

broken down to glucose to provide energy

3 main subtypes for carbohydrates

monosaccharides

disaccharides

polysaccharides

monosaccharides

3 structural isomers: glucose, fructose, galactose

3-7 carbons

disaccharides

form when 2 monosaccharides are linked in a dehydration reaction

joined by glycosidic bond

1-2 glycosidic bond

polysaccharides

long chain of monosaccharides joined by glycosidic linkages

1-4 glycosidic bond

1-6 glycosidic bond

amylose

unbranched glucose monomers in a 1-4 glycosidic bond

amylopectin

branched glucose monomers in 1-4 and 1-6 glycosidic bonds

starch

composed of amylose and amylopectin

cellulose

glucose monomers linked in unbranched chains by beta 1-4 glycosidic linkages

chitin

the hard exoskeleton of arthropods is composed of this polysaccharide

lipids

diverse group of hydrophobic non polar hydrocarbons

long term energy stores

building blocks for some hormones

important component of cell membranes

2 main components of fats

glycerol

fatty acids

triacylglycerol

formed by joining 3 fatty acids to a glycerol backbone

ester linkage

how glycerol molecules are attached to the fatty acids

saturated fatty acids

contain no C=C double bonds in the backbone

packed tightly and exist as solids at room temperature

unsaturated fatty acids

contain at least 1 C=C double bond in backbone

most unsaturated fats are liquids at room temperature referred to as oils

cis

acids have kink in the chain

they cannot be packed tightly

liquid at room temperature

trans

acids have no kink

can be created through processing

phospholipid

molecule with 2 fatty acids and a modified phosphate group attached to a glycerol backbone

phosphate may be modified by addition of charged or polar chemical groups

2 common chemical groups that attached are choline and serine

proteins

most abundant organic molecules

have a diverse range of functions:

regulatory

structural

protective

transport

enzymes

toxins

multiple polypeptides

types of enzymes

catabolic

anabolic

catalytic

catabolic

break down substrates

anabolic

build more complex molecules

catalytic

affect rate of reaction

amino acids

monomers of proteins

the sequence and number of amino acids determine protein shape, size, and function

linked via peptide bond formation ( dehydration synthesis reaction

polypeptide

a chain of amino acids joined together in peptide linkages

protein shape has 4 levels of structure

primary

secondary

tertiary

quaternary

primary protein structure

amino acid sequence determined by gene encoding that protein

a change in that nucleotide sequence of DNA could lead to a change in amino acid

this could lead to a change in protein structure and function

secondary protein structure

local folding of polypeptide

alpha helix- formed by hydrogen bond between oxygen in carbonyl group and an amino acid 4 positions down the chain

beta pleated sheet- hydrogen bonding between atoms on the backbone of the polypeptide chain

tertiary protein structure

unique 3D structure of polypeptide

chemical interactions between R groups on amino acids

determined by a variety of chemical interactions:

hydrophobic interactions

ionic bonding

hydrogen bonding

disulfide linkages

quaternary protein structure

interactions between several polypeptides that make up a protein

weak interactions between subunits help stabilize the structure

denaturation

changes in protein structure that leads to changes in function

changes in pH and temperature will alter primary structure of protein

nucleic acids

constitute the genetic material of living organisms

2 types:

DNA and RNA

locations:

nucleus of eukaryotic cells

mitochondria

chloroplasts

prokaryotic cells

DNA

codes for the genome of the cell

chromatin

complex of DNA and histone proteins