AP Biology Unit 1 Chapter 3

Which part of an amino acid is always acidic?

Carboxyl functional group

Which of these functional groups is characteristic of alcohol?

D

Which of these is a hydroxyl group?

D

What could happen if a mutation in a gene caused a hydrophobic amino acid in a polypeptide to be replaced by a hydrophilic amino acid?

The new amino acid would not form the same interactions with hydrophobic R groups, and the protein's shape would likely be affected.

Which of the following statements is an accurate description of proteins?

The primary structure of a protein is the order of amino acids in a polypeptide, as coded for in the DNA of a gene.

True or false? Enzymes in the digestive tract catalyze hydrolysis reactions.

True

True or false? Peptidoglycan is a polysaccharide found only in bacteria.

True

If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?

75

In the interactive structure window, click the "Show sections A, B, and C" button. Which of the three sections forms an alpha helix?

A

Which amino acid--A, B, or C--actually falls between the other two in lysozyme's primary structure (the order of the amino acids in the polypeptide chain)?

A

Which of the functional groups behaves as a base?

A

Which one of these is an amino group?

A

Which of the following statements about the formation of polypeptides from amino acids is true?

A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.

What do fats, steroids, and waxes have in common?

(b) Low solubility in water

Match the monomers with their polymers.

-Nucleic acid polymers are made up of nucleotide monomers. -Carbohydrate polymers are made up of simple sugar monomers. -Protein polymers are made up of amino acid monomers.

Match the words in the left-hand column with the appropriate blank in the sentences in the right-hand column.

1. A monosaccharide cannot be hydrolyzed any further. 2. A carbohydrate that yields many monosaccharides when hydrolyzed is a polysaccharide . 3. A simple sugar is composed of equal parts carbon and water, which gave rise to the general name of any sugar as a carbohydrate . 4. Lactose, the sugar in milk, is a disaccharide, because it can be split into two monosaccharides.

Drag the terms on the left to the appropriate blanks on the right to complete the sentences about the observational study.

1. A relative risk (RR) of 1 means the risk of heart disease is the same compared to an equivalent intake of carbohydrates. 2. An RR greater than 1 means the risk of heart disease is higher compared to an equivalent intake of carbohydrates. 3. An RR less than 1 means the risk of heart disease is lower compared to an equivalent intake of carbohydrates. 4. The RR for monounsaturated fat is 0.81, suggesting that increasing intake of this type of fat by 5% decreases the risk of heart disease. 5. The RR for polyunsaturated fat is the lowest among the fats tested, suggesting that these fats are most beneficial for cardiovascular health. 6. The RR for saturated fat is 1.17. For each 5% increase in energy consumed in this form of fat, there is a 17% increase in heart disease risk. 7. The RR of trans fat is the hghest among the types of fats tested, suggesting that these fats pose the greatest health risk. 8. For each increase of 2% in energy from trans fats, there is a 93% increased risk of heart disease.

Complete the following vocabulary exercise relating to the level of structure in proteins. Match the words in the left-hand column with the appropriate blank in the sentences in the right-hand column.

1. Quaternary structure is the result of two or more protein subunits assembling to form a larger, biologically active protein complex. 2. Tertiary structure is achieved when a protein folds into a compact, three-dimensional shape stabilized by interactions between side-chain R groups of amino acids. 3. Primary structure is the sequence of amino acids in a protein. 4. Secondary structure describes the alpha-helices and beta-sheets that are formed by hydrogen bonding between backbone atoms located near each other in the polypeptide chain.

If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand?

3'-TAAACG-5'

Which of these is a carbonyl group?

C

Which of the following is a hydrocarbon?

C3H8

Which molecules show an appropriate number of bonds around each carbon atom? Select the three that apply.

CH3CH2CHOH CH2CHCH3 a six membered ring with two O atoms attached and a double helix

Select the statement that is incorrect.

All carbohydrates have the general formula Cn(H2O)n.

Which complex carbohydrate contains only a-1,4-glycosidic linkages?

Amylose

Which of the following is not attached to the central carbon atom in an amino acid?

An oxygen

Which of these groups plays a major role in energy transfer?

B

Which of these is a phosphate group?

B

Which of the following complex carbohydrates is listed with its correct function?

Cellulose: structural component of plant cell walls

The flow of genetic information in a cell goes from __________.

DNA to RNA to protein

Which of these groups is characteristic of thiols?

E

Which of functional groups listed below behaves as an acid?

F

Which of these is a carboxyl group?

F

Sort the statements into the appropriate bins depending on whether they represent factors that varied from participant to participant at the start of this study, factors that were consistent from the start of the study, and factors that were measured in the study.

Factor(s) that varied from the start of the study: -smoking status (smoking vs. non-smoking) -total food intake -activity level -percentage of different types of fats eaten Factor(s) kept consistent from the start of the study -sex of participant Outcome(s) measured in the study -number of non-fatal heart attacks -deaths from coronary heart disease Submit

Drag the labels onto the flow chart to identify the elements and limitations of your experimental design.

Hypothesis: Trans Fats have a negative effect on cardiovascular health Prediction: Eating more trans fats will lead to the greater cardiovascular health problems Experiment: Feed some people a diet high in trans fat and feed others a diet low of trans fats Data Collection: Take blood samples to measure fat and cholesterol levels in the two groups Practical: Are other lifestyle factors affecting cardiovascular health Ethical: Are we putting in?dividuals' health at risk?

Which molecule is not a carbohydrate?

Lipid

Which of the following statements about monosaccharide structure is true?

Monosaccharides can be classified according to the spatial arrangement of their atoms. Submit

Which polysaccharide contains a modified monosaccharide?

Peptidoglycan

Which polymers are composed of amino acids?

Proteins

Which of these is NOT a lipid?

RNA

Which of the following best describes cis-trans isomers?

They differ in their spatial arrangement around inflexible double bonds. Submit

A function of cholesterol that does not harm health is its role _____.

as a component of animal cell membranes

Dr. Haxton told one of his students, "To move in the bloodstream, fats need the help of phospholipids." What would a good student say?

Yes. Nonpolar molecules aren't compatible with water.

Which of these illustrates the secondary structure of a protein?

a structure with a helical and sheet regions

Classify these amino acids as acidic, basic, neutral polar, or neutral nonpolar. Drag each item to the appropriate bin.

acidic- glutamic acid basic- none neutral polar- tyrosine, threonine neutral nonpolar- tryptophan, valine

Classify these amino acids as acidic, basic, neutral polar, or neutral nonpolar. Drag each item to the appropriate bin.

acidic- none basic- arginine neutral polar- asparagine, glutamine neutral nonpolar- alaine

Classify these amino acids as acidic, basic, neutral polar, or neutral nonpolar. Drag each item to the appropriate bin.

acidic- none basic- lysine neutral polar- serine neutral nonpolar- methionine, phenyalanine

Drag one molecule and one chemical property to each bin. If one property can apply to more than one functional group, choose the best answer for each functional group.

alcohol -is polar and makes compounds more soluble in water carboxylic acid -acts as an acid aldehyde -may be a structural isomer of a ketone thiol -forms disulfide bonds amine -acts as a base organic phosphate -contributes negative charge

Proteins are polymers of _____.

amino acids

Which of the three different representations of protein structure is most useful for observing the path of the protein chain from one amino acid to the next?

backbone

The large diversity of shapes of biological molecules is possible because of the extensive presence of _____ in the molecules.

carbon

Citric acid makes lemons taste sour. Which of the following is a functional group that would cause a molecule such as citric acid to be acidic?

carboxyl

Plant cell walls consist mainly of _____.

cellulose

Palm oil and coconut oil are more like animal fats than are other plant oils. Because they __________ than other plant oils, they may contribute to cardiovascular disease.

contain fewer double bonds

What is another name for a condensation reaction?

dehydration

Sucrose is formed when glucose is joined to fructose by a(n) __________.

glycosidic linkage

Which of these is a phospholipid?

http://session.masteringbiology.com/problemAsset/1100498/3/0509a5.jpg

Most organic compounds contain carbon and _____.

hydrogen

The secondary structure of a protein results from _____.

hydrogen bonds

The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases.

hydrogen bonds

What is the name of the process during which a bond between two monomers is broken?

hydrolysis

Defensive proteins are manufactured by the _____ system.

immune

Molecules that have the same chemical formula (same numbers of each atom) but different three-dimensional shapes are called __________.

isomers

The characteristic that all lipids have in common is that __________.

none of them dissolves in water

The building blocks, or monomers, of nucleic acid molecules are called __________.

nucleotides

Which monomers make up RNA?

nucleotides

Which of these is rich in unsaturated fats?

olive oil

A hydrophobic amino acid R group (side group) would be found where in a protein?

on the inside of the folded chain, away from water

Which of these does NOT contain a structural protein?

ovalbumin

What type of bond joins the monomers in a protein's primary structure?

peptide

Tertiary structure is NOT directly dependent on _____.

peptide bonds

What functional group is commonly used in cells to transfer energy from one organic molecule to another?

phosphate

A nucleotide is composed of a(n) _____.

phosphate group, a nitrogen-containing base, and a five-carbon sugar

Identify the level(s) of protein structure present in this molecule.

primary secondary tertiary quaternary

The four main categories of large biological molecules present in living systems are __________.

proteins, nucleic acids, polysaccharides, and lipids

Arrow D is indicating a _____ protein.

receptor

Which of the three different representations of protein structure is most useful for studying the interior shapes formed by the folds of the protein?

ribbon

This figure is an example of a(n) _____.

saturated fat

Some regions of a polypeptide may coil or fold back on themselves. This is called __________, and the coils or folds are held in place by __________.

secondary structure ... hydrogen bonds

Which of the three different representations of protein structure is most useful for studying the exterior of the protein?

spacefill

Arrow A is indicating a(n) _____ protein.

structural

Variations in the reactive properties of different organic molecules are most closely associated with __________.

the presence or absence of functional groups

A dehydration reaction (or condensation reaction) is the process in which __________.

water molecules are produced as a polymer is formed from monomers

Highlight all the atoms of the four functional groups, but do not highlight any bonds. When you click on each atom, it will change color. To deselect an atom, click on it again. Before you submit, check that you have not selected any bonds.

−OH, −SH, −NH2, and −OPO2−3