AP Biology Unit 1

Proteios

first or primary

Water has high...

specific heat

mole

the SI base unit used to measure the amount of a substance

Solvent

the dissolving agent

Proteins are _____ percent dry weight of cells

50%

dehydration synthesis

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

polar covalent bond

A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.

surface tension

A measure of how difficult it is to stretch or break the surface of a liquid

hydroxide ion

A negatively charged ion made of oxygen and hydrogen.

Purines

Adenine and Guanine

Calorie

Amount of energy needed to raise temperature 1 gram of water 1 degree C

Adhesion

An attraction between molecules of different substances

Which statement describes how water is pulled up through the xylem to the leaves of the plant?

As water exits the leaf, hydrogen bonding between water molecules pulls more water up from below.

cohesion

Attraction between molecules of the same substance

A student wants to modify model 1 so that it represents an RNA double helix instead of a DNA double helix. Of the following possible changes, which would be most effective in making model 1 look more like RNA than DNA? A. Changing the sequence of the base pairs B. Changing the deoxyriboses to riboses by adding -OH groups C. Changing the shapes of the nitrogenous bases to match those shown in model 2 D. Changing the sugar-phosphate backbone to a ribbon, as shown in model 3

B

Different polysaccharides are used by plants for energy storage and structural support. The molecular structures for two common polysaccharides are shown in Figure 1. Starch is used by plants for energy storage, and cellulose provides structural support for cell walls. The monomer used to construct both molecules is glucose. Based on Figure 1, which of the following best compares the atomic structures of starch and cellulose? A. Starch is composed of carbon, hydrogen, and oxygen, while cellulose also contains nitrogen. B. Starch and cellulose are composed of repeating glucose monomers; however, in cellulose every other glucose monomer is rotated 180 degrees. C. Starch is composed of monomers that each have a CH2OH group, while cellulose only has a CH2OH group on every other monomer. D. Starch and cellulose are composed of identical monomers and therefore have identical structures.

B

Figure 1 represents a segment of DNADNA. Radiation can damage the nucleotides in a DNADNA molecule. To repair some types of damage, a single nucleotide can be removed from a DNADNA molecule and replaced with an undamaged nucleotide. Which of the four labeled bonds in Figure 1 could be broken to remove and replace the cytosine nucleotide without affecting the biological information coded in the DNADNA molecule?

Bonds Y and Z at the same time

Hydrolysis

Breaking down complex molecules by the chemical addition of water

Major element of life are...

C, H, N, O, P, S

Lipids structure

Chains(normally very long), and can be saturated or unsaturated

organic compounds

Compounds that contain carbon

Isomers

Compounds with the same formula but different structures.

A polypeptide is polymer of amino acids held together by peptide bonds. The process of dehydration synthesis creates these peptide bonds, as shown in Figure 1. As shown in Figure 1, an amino acid must have which of the following properties in order to be incorporated into a polypeptide? A. The ability to remain stable in the presence of water molecules B. An R-group that is compatible with the R-group of the last amino acid incorporated C. A central carbon atom that reacts with a nitrogen atom to form the peptide bond D. The ability to form a covalent bond with both its NH2 group and its COOH group

D

Nucleic acids

DNA and RNA

Quantitative Data

Data that is in numbers

structure of proteins

H3N along with a backbone(carbon) and a random breakoff group

nucleic acids structure

Has a base and a sugar, sometimes has a phosphate

thermal energy

Heat energy

Enzymes

Proteins that speed up chemical reactions

heat of vaporization

The amount of energy required for the liquid at its boiling point to become a gas

specific heat

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

carbohydrates structure

chains or rings(chains are shorter)

dependent variable

The measurable effect, outcome, or response in which the research is interested.

Protein structure and function are sensitive to _______ and ________ conditions.

chemical, physical

Pyrimidines

cytosine, thymine, uracil

evaporative cooling

The process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from the liquid to the gaseous state.

molecular mass

The sum of the masses of all the atoms in a molecule

The figure presents a lake covered by a layer of ice. The air above the ice is negative 5 degrees Celsius. Immediately below the ice, the temperature of the lake water is 0 degrees Celsius. The water deeper in the lake is 4 degrees Celsius. There is a fish in this deeper water. As shown in the diagram, when environmental temperatures drop below freezing, a layer of ice typically forms on the surface of bodies of freshwater such as lakes and rivers. Which of the following best describes how the structure of ice benefits the organisms that live in the water below?

The water molecules in ice are farther apart than those in liquid water, so the ice floats, maintaining the warmer, denser water at the lake bottom.

Hydrophobic

Water fearing

aqueous solution

a solution in which the solvent is water

The hypothesis is either______ or ________ based on evidence.

accepted, rejected

Secondary level of protein structure

alpha helix (coil) and beta-pleated sheet; Acidic and Basic Amino Acids form salt bridges (ionic bonds); cysteines can form disulfide bonds

Primary level of protein structure

amino acid sequence; peptide bonds; 20 different Amino Acids

monomer of proteins

amino acids held together by peptide bonds

Tertiary level of protein structure

bonding between side chains(R groups) of amino acids; Hydrogen Bonds, ionic bonds, disulfide bridges, and van der waals interactions

What are the four classes of macromolecules?

carbohydrates, lipids, proteins, nucleic acids

Molarity

the number of moles of solute per liter of solution

hydronium ion

the positive ion formed when a water molecule gains a hydrogen ion

kilocalorie

the quantity of heat required to raise the temperature of 1 kilogram of water by 1 degree Celsius

hydration shell

the sphere of water molecules around each dissolved ion

organic chemistry

the study of all chemicals containing carbon

Quaternary level of protein structure

two or more polypeptide chains combine

independent variable

variable that is manipulated

non-polar doesn't mix with...

water

Hydrophilic

water loving

ocean acidification

when CO2 dissolves in seawater, it reacts with water to form carbonic acid, which lowers ocean pH

Proteins are made up of

carbon, hydrogen, oxygen, nitrogen, sulfur(sometimes)

Most common functional groups

hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, phosphate, methyl

Enantiomers

isomers that are mirror images of each other

Polymers

large compound formed from combinations of many monomers

qualitative data

descriptive data

different structures=.....

different properties

Double covalent bond

ends in -ene

Macromolecules are

giant molecules, two or more polymers bonded together

polar molecule

molecule with an unequal distribution of charge, resulting in the molecule having a positive end and a negative end

Nucleotides

monomers of nucleic acids

monomer of carbohydrates

monosaccharides, disaccharides, polysaccharides

monomer of nucleic acids

nucleotides

Chaperonins

protein molecules that assist the proper folding of other proteins

Based on the figure, which statement best describes the observed relationship between atmospheric CO2CO2 enrichment and plant growth under ideal and stressed conditions? A. The increase in atmospheric CO2 had no observable effect on plant growth under either ideal or stressed conditions. B. The increase in atmospheric CO2 resulted in a greater increase in plant growth under ideal conditions than under stressed conditions. C. The increase in atmospheric CO2 resulted in a greater increase in plant growth under stressed conditions than under ideal conditions. D. The increase in atmospheric CO2 resulted in an inhibition of plant growth under both ideal and stressed conditions.

C

Different polysaccharides are used by plants for energy storage and structural support. The molecular structures for two common polysaccharides are shown in Figure 1. Starch is used by plants for energy storage, and cellulose provides structural support for cell walls. The monomer used to construct both molecules is glucose. Which of the following best describes the process that adds a monosaccharide to an existing polysaccharide? A. The monosaccharide is completely broken down by a specific enzyme and then the atoms are reorganized and made into a polysaccharide. B. Ionic bonds are formed between adjacent carbon atoms of the monosaccharide and the polysaccharide by adding water(H2O) and a specific enzyme. C. A specific enzyme removes the hydrogen (H) from the monosaccharide and the hydroxide (OH) from the polysaccharide, creating a bond between the two and creating a water (H2O) molecule. D. A specific enzyme removes two hydroxides (OH), one from the monosaccharide, and one from the polysaccharide, creating a bond between the two monosaccharides and creating a hydrogen peroxide (H2O2) molecule.

C

Phosphorous (P) is an important nutrient for plant growth. Figure 1 shows Arabidopsis thaliana plants grown under phosphorus‐sufficient (left) and phosphorus‐starved (right) conditions for six weeks. Which of the following is the most likely reason for the difference in leaf growth? A. The phosphorus-starved plant was unable to synthesize both the required proteins and lipids, limiting growth. B. The phosphorus-starved plant was unable to synthesize both the required proteins and carbohydrates, limiting growth. C. The phosphorus-starved plant was unable to synthesize both the required nucleic acids and lipids, limiting growth. D. The phosphorus-starved plant was unable to synthesize both the required carbohydrates and nucleic acids, limiting growth.

C

base

A substance that decreases the hydrogen ion concentration in a solution.

Single covalent bond

ends in -ane

Triple covalent bond

ends in -yne

kinetic energy

energy of motion

Protein Functions

enzyme catalysis, defense, transport, support, motion, regulation, storage

Carbon can form up to how many covalent bonds?

four bonds

Carbon has ___ valence electrons

four electrons

Monomer of Lipids

glycerol and fatty acids

cis-trans isomers

have the same covalent bonds but differ in spatial arrangements

The head of a lipid is.....

hydrophilic

The tails of a lipid are...

hydrophobic

solute

A substance that is dissolved in a solution.

Carbohydrates are composed of

carbon, hydrogen, oxygen

Different polysaccharides are used by plants for energy storage and structural support. The molecular structures for two common polysaccharides are shown in Figure 1. Starch is used by plants for energy storage, and cellulose provides structural support for cell walls. The monomer used to construct both molecules is glucose. Based the information provided, which of the following statements best describes why starch and cellulose provide different functions in plants? A. The differences in the assembly and organization of the monomers of these two polymers result in different chemical properties. B. Since starch and cellulose are composed of identical monomers, the cellular environment where they are located controls their function. C. The monomers of cellulose are connected by covalent bonds, making it ideal for structural support. D. The monomers of starch are connected by ionic bonds, making it ideal for energy storage for plants.

A

Figure 1 shows three amino acids that are part of a polypeptide chain. Figure 2 shows the same section of the chain after a mutation has occurred. How might this change affect the structure and function of the protein? A. The R-group of the new amino acid, valine, has different chemical properties than the R-group of cysteine. This will cause the protein to misfold and not function properly in the cell. B. The new amino acid, valine, has replaced cysteine in the new protein. Since the number of amino acids has remained the same, there will be no change in the three-dimensional folding, or function, of the protein. C. Since this is a linear section, it does not influence protein folding. Thus, there will be no change in protein structure or function. D. Since the new amino acid is bounded on one side by an amino acid with a negatively charged R-group and by an amino acid on the other side with a positively charged R-group, the charges will balance and the protein will fold as usual.

A

Thalidomide

A mild tranquilizer that, taken early in pregnancy, can produce a variety of malformations of the limbs, eyes, ears, and heart.

hydrogen ion (H+)

A positively charged ion formed of a hydrogen atom that has lost its electron

buffer

A solution that minimizes changes in pH when extraneous acids or bases are added to the solution.

acid

A substance that increases the hydrogen ion concentration of a solution.

Which of the following best describes a structural similarity between the two molecules shown in Figure 1 that is relevant to their function? A. Both molecules are composed of the same four nucleotides, which allows each molecule to be produced from the same pool of available nucleotides. B. Both molecules are composed of the same type of five-carbon sugar, which allows each molecule to act as a building block for the production of polysaccharides. C. Both molecules contain nucleotides that form base pairs with other nucleotides, which allows each molecule to act as a template in the synthesis of other nucleic acid molecules. D. Both molecules contain nitrogenous bases and phosphate groups, which allows each molecule to be used as a monomer in the synthesis of proteins and lipids.

C

Which of the following describes a key difference among the 20 amino acids that are used to make proteins? A. Only some amino acids have an R-group B. Only some amino acids have a carboxyl group (COOH) C. Some amino acids are hydrophobic. . Some amino acids contain the element phosphorus.

C

Which of the following is common feature of the illustrated reactions showing the linking of monomers to form macromolecules? A. Two identical monomers are joined by a covalent bond. B. Two different monomers are joined by a covalent bond. C. Monomers are joined by a covalent bond, and a water molecule is produced. D. Monomers are joined by ionic bonds, and a water molecule is produced.

C

Figure 1 shows a short segment of a double-stranded nucleic acid molecule. Which of the following statements is correct about the molecule shown in Figure 1? A. It is RNA because of the relative direction of the two strands. B. It is RNA because of the number of different nucleotides found in the molecule C. It is DNA because of the nature of the hydrogen bonds between guanine and cytosine. D. It is DNA because of the nucleotides present.

D

Which feature of model 1 best illustrates how biological information is coded in a DNADNA molecule? A- The 5′ and 3′ labels at the ends of each strand B- The labeling of the hydrogen bonds between base pairs C- The lines connecting sugars and phosphate groups that represent covalent bonds D- The linear sequence of the base pairs

D

experimental group

In an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable.

control group

In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

Lipids are made of

carbon, hydrogen, oxygen(small amounts)

Nucleic acids are made of

carbon, hydrogen, oxygen, nitrogen, phosphorus(sometimes)

Different polysaccharides are used by plants for energy storage and structural support. The molecular structures for two common polysaccharides are shown in Figure 1. Starch is used by plants for energy storage, and cellulose provides structural support for cell walls. The monomer used to construct both molecules is glucose. Mammals do not produce digestive enzyme B. However, sheep and cattle are two types of mammals that contain microorganisms in their digestive tract that produce enzyme. Which of the following would most likely occur if cattle lost the ability to maintain a colony of microorganisms in their digestive tract? A. Cattle would no longer be able to synthesize cellulose. B. Cattle would have to convert cellulose to starch before digesting it. C. Cattle would have to start producing enzyme D. Cattle would no longer be able to use cellulose as a primary source of glucose.

D

Structural Isomer

differ in the covalent arrangements of their atoms