AP Biology Midterm

Emergent Properties

result from the arrangement and interactions of parts within a system

characterize non-biological entities within a system

Reductionism

the reduction of complex systems to simpler components that are more manageable to study

Biology balances reductionism with the study of emergent properties

Ex: studying the interactions of DNA with other molecules

System Biology

Constricts models for the dynamic behavior of whole biological systems

Eukaryotic cell

has membrane-enclosed organelles, the largest of which is usually the nucleus

Prokaryotic cell

simpler and usually smaller, and does not contain a nucleus or other membrane-enclosed organelles

Feedback mechanisms

allow biological processes to self-regulate

negative feedback

as more of a product accumulates, the process that creates it slows and less of the product is produced

positive feedback

as more of a product accumulates, the process it creates speeds up and more of the product is produced

three-domain system

plantae, animalia, fungi

Microtubule structure of a cilium

9+2 doublet

(cilia lines the inside of the windpipe)

Elements

substance that cannot be broken down to other substances by clean reactions

Compound

two or more elements

number of elements essential to life

25 out of 92 elements

(carbon, hydrogen, oxygen, nitrogen are most important out of this number)

radioactive isotopes

decay spontaneously, giving off particles and energy

chemically inert

describes elements with a full valence shell

hydrogen bonds

forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom

electronegative partners

usually oxygen or nitrogen

(relating to electronegativity)

‘Hot Spots’

positive/negative charges resulting from asymmetrically distributed electrons in molecules or atoms

Van der Waals interactions

happen between molecules that are close together as a result of these charges

(can be strong, as between molecules of a gecko’s toe hairs and a wall surface)

polarity of water

opposite ends have opposite charges

(allows water molecules to form hydrogen bonds with other molecules)

four properties of water

cohesive behavior

ability to moderate temperature

expansion upon freezing

versatility as a solvent

cohesion

hydrogen bonds hold water molecules together

(helps the transport of water against gravity in plants)

adhesion

attraction between different substances

zylum vessels

another name for water conducting cells

functional groups

the components of organic molecules that are most commonly involved in chemical reactions

(the number and arrangement give each molecule its unique properties)

seven functional groups

hydroxyl group: OH or -HO

carbonyl group: C=O or CO

amino group: H2N or NH2

sulfhydryl group: S-H or SH

phosphate group: PO4

methyl group: CH3

carboxyl group: CO2H or COOH

ATP (adenosine triphosphate)

phosphate molecule which is the primary energy-transferring molecule in the cell

Isomers

have the same molecular formula, but different structural formula and different properties

structural isomers

different covalent arrangements

geometric isomers

same covalent arrangements that differ in spatial arrangements

enantiomers

mirror images of each other

(important in the pharmaceutical industry)

Four classes of macromolecules

carbohydrates, lipids, proteins, and nucleic acids

macromolecules

large molecules composed of covalently bonded atoms

polymer

long molecule consisting of many similar building blocks (monomers)

(carbs, proteins, nucleic acids)

condensation reaction

occurs when two monomers bond together through the loss of a water molecule

(more specifically known as a dehydration reaction)

enzymes

macromolecules that speed up the dehydration process

hydrolysis

essentially the reverse of a dehydration reaction

(polymers are disassembled to monomers by this process)

Monosaccharides

simple sugars, also the simplest carbs

polysaccharides

carbohydrate macromolecules, polymers composed of many sugar building blocks

Classification of monosaccharides

• The location of the carbonyl group (as aldose or ketose)

• The number of carbons in the carbon skeleton

Disaccharide

formed when a dehydration reaction forms two monosaccharides

structure and function

determined by its sugar monomers and positions of glycosidic linkages

starch

Plant saccharide

glycogen

animal saccharide

polysaccharide cellulose

major component of the tough wall of plant cells

alpha and beta

ring forms for glucose

distinguishes starch from cellulose, which are both polymers of glucose

Lipids

include fats, oils, and waxes

Six Classes

• Fatty Acids

• Eicosanoids

• Glycerides

• Steroids

• Phospholipids

• Glycolipids

Triglycerides

three fatty acids affected by dehydration synthesis to one molecule of glycerol

steroids

• involved in cell membrane structure

• include s-x hormones and hormones regulating metabolism

• are important in lipid digestion

Six important functions of proteins

• Structural proteins

• Contractile proteins

• Transport proteins

• Enzymes

• Buffering proteins

• Antibodies

Amino acids

contain an amino group, a carboxylic group, and a radical group

polypeptides

linear segments of amino acids held together by peptide bonds

four levels of protein structure

• primary structure (amino acid sequence)

• secondary structure (amino acid interactions)

• tertiary structure (complex folding)

• quarternary structure (protein complexes)

Reactants

interact to yield a product by binding to the active site of the enzyme

(aka substrate)

cofactors

must bind to the enzyme before substrate binding can occur

Make up of nucleotide

made up of phosphate, pentose sugar, nitrogenous base

nucleoside

portion without phosphate group

pyrimidines

thymines, uracil, and cytosine

• six-membered ring

purines

adenosine and guanine

• six-membered ring fused to a five-membered ring

a purine

a ____ will always base pair with a pyrimidine molecule

adjacent molecules

joined by covalent bonds that form between the -OH group on the 3’ carbon of one nucleotide and the phosphate on the 5’ carbon on the next

(these links create a backbone of sugar-phosphate units with nitrogenous bases as appendages)

Polynucleotide

a hydrogen bond is a ______