Bio test

18. Amino acids all have the same general morphology except for the:

'R' Group

9. What 3 letters do enzymes typically end in?

-ase

25. What is the pOH of a solution that has a pH of 2?

12

28. The pOH of sea water is 5. What is its pH?

9

16. Heating a protein or lowering the pH beyond a protein's range of tolerance can result in denaturing the protein by (A) breaking the weak hydrogen bonds, causing the protein to unwind or change shape (B) breaking the strong covalent bonds of the protein's primary structure (C) dissolving peptide bonds between the amino acids in the polypeptide chain (D) removing the heme or other group that gives the protein its identity and chemical characteristics (E) causing the molecule to fold and wind tighter, covering the surface receptor sites

A Breaking of hydrogen bonds will result in the change to a more stable form of a protein.

Polysaccharides are best described as: (A) complex molecules such as starches that are composed of many chains of sugar monomers (B) chains of amino acids joined by peptide bonds (C) molecules made of glycerol and three fatty acid chains (D) nucleotides arranged in a helical pattern (E) a five- or six-carbon sugar molecule bonded to an aldehyde or ketone group

A Carbohydrate monomers make up polysaccharides.

I. NAD+ II. ATP III. Uracil IV. Thymine 19. Which of the compounds serve(s) as an electron carrier in cellular respiration? (A) I only (B) I and II (C) II only (D) I and III (E) III and IV only

A Only NAD+ is an electron carrier in the group listed.

What converts ammonia into nitrates during the nitrogen cycle? A) Bacteria B) Fungi C) Green plants D) Viruses E) Protists

A) Bacteria

The attraction between the hydrogen of one H2O molecule and an oxygen of another H2O molecule is an example of A) a hydrogen bond B) a polar covalent bond C) Van der Waals forces D) a hydrophobic interaction E) a non-polar covalent bond

A) a hydrogen bond

Which of the following is caused by water's intramolecular forces? A) dipole nature B) easy dissociation into H+ and OH- ions C) hydrogen bonds D) low density of ice E) all of the above

A) dipole nature

Each of the following are properties of water EXCEPT A) it has a low heat of vaporization B) it expands when it freezes C) it is a useful solvent D) it has cohesive properties E) it has a high specific heat

A) it has a low heat of vaporization

Water sustains life on Earth by all of the following properties EXCEPT A) low surface tension from double covalent bonds B) strong capillary action from cohesion and adhesion C) neutral pH from the equal concentrations of H+ and OH- ions D) ability to act as a universal solvent because of the polarity of the H2O molecule E) low density of its solid form because of hydrogen bonds

A) low surface tension from double covalent bonds

Which of the following are responsible for nitrogen entrance into an ecosystem? A) rain, soil, and bacteria B) respiration, nitrogen fixation, and decomposition C) denitrification, ammonification, and photosynthesis D) water, fungus, and humus E) denitrification, bacteria, and respiration

A) rain, soil, and bacteria

The primary abiotic nitrogen source in the nitrogen cycle is A) the atmosphere B) the ocean C) the soil D) nutrients E) plants

A) the atmosphere

The primary environmental abiotic carbon source for the carbon cycle is A) the carbon dioxide in the air B) the carbon dioxide in the soil C) the carbon monoxide in the air D) the carbon monoxide in the water E) carbon ions in the water

A) the carbon dioxide in the air

The primary environmental abiotic carbon source for the carbon cycle is A) the carbon dioxide in the air B) the carbon dioxide in the water C) the carbon monoxide in the air D) the carbon monoxide in the water E) the carbon dioxide in plants

A) the carbon dioxide in the air

The fluid mosaic model of the cell membrane states that A) the hydrophobic zone consists of the hydrophobic, nonpolar tails of phospholipids located in between hydrophilic, polar heads of phospholipids B) the hydrophobic zone consists of the hydrophilic, nonpolar tails of phospholipids located in between hydrophobic, polar heads of phospholipids C) the hydrophilic zone consists of the hydrophobic, nonpolar tails of phospholipids located in between hydrophilic, polar heads of phospholipids D) the hydrophilic zone consists of the hydrophobic, nonpolar tails of phospholipids located in between hydrophobic, polar heads of phospholipids E) a layer of globular protein is located in between two phospholipid outer membranes

A) the hydrophobic zone consists of the hydrophobic, nonpolar tails of phospholipids located in between hydrophilic, polar heads of phospholipids

I. NAD+ II. ATP III. Uracil IV. Thymine 18. Which of the compounds are nucleotides? (A) I and II only (B) I, II, and III only (C) II and III only (D) III and IV only (E) I, II, III, and IV

All of the above are nucleotides or nucleotide triphosphates.

1. The monomer, building block, of proteins Amino Acid Fatty Acid Nucleotide monosaccharide

Amino Acid

What does pH measure?

Amount of Hydrogen/Hydronium Ions

7. All of the following statements about potential energy are true EXCEPT (A) fixed potential energy states for electrons are called electron shells or energy levels (B) electrons with the highest potential energy are closest to the nucleus of the atom (C) potential energy of electron exists in discrete amounts called quanta (D) matter tends to move to the lowest state of potential energy (E) electrons with greater energy exist in outer electron shells

B Electrons with the highest potential energy are farthest from the nucleus.

Storage of fat by the body is advantageous primarily because fats (A) are insoluble and chemically stable (B) yield, gram for gram, more than twice as much energy as complex carbohydrates (C) can be digested with less energy and fewer enzymes than carbohydrates and proteins (D) store almost all potential energy in chemical bonds (E) are much easier to produce from surplus molecules that have been broken down by digestive enzymes

B Fats yield ~9Calories per gram while Carbohydrates and proteins yield ~4 Calories per gram.

8. The insolubility of fats in water is due primarily to (A) the many nonpolar C-H bonds (B) the ester linkage between a hydroxyl group and a carboxyl group (C) the presence of glycerol in the structure makeup (D) the variety of fatty acids in a fat molecule (E) the large number of double bonds between carbon atoms

B Nonpolar C-H bonds are responsible for the insolubility of fats in water.

The carbon cycle I. has increased atmospheric carbon dioxide levels, causing global warming II. involves photosynthetic processes III. leads to the reduction of aquatic biomass A) I only B) II only C) III only D) I and II only E) I, II and III only

B) II only

Which of the following is the direction water moves across a selectively permeable membrane? A) Water will move from a region of lower water potential to an area of higher water potential. B) Water will move from a region of higher water potential to an area of lower water potential. C) Water can move in either direction across the membrane. D) Water will not move across the membrane. E) Water will only move if the water potentials are above a certain threshold.

B) Water will move from a region of higher water potential to an area of lower water potential.

23. A solution with a pH of 8.6 would be...

Base

A polymer of glucose that serves as a storage macromolecule in animals is (A) chitin (B) starch (C) glycogen (D) cellulose (E) amylase

C Cellulose is found in the cell walls of plants. Chitin is found in the cell walls of fungi. Starch is an energy store in plants. Glycogen is stored in the liver of animals.

9. Lipids with four fused carbon rings and various functional groups attached are known as (A) phospholipids (B) saturated fats (C) steroids (D) fatty acids (E) chitin

C Cholesterol based steroid hormones display a "backbone" of four fused ring structures.

The twenty common amino acids differ from each other in the composition of a covalently bonded side chain known as a(n) (A) polypeptide (B) dipeptide (C) R group (D) amino group (E) carboxyl group

C R groups are unique to each individual amino acid.

Which component of the extracellular matrix of an animal cell can communicate through the hydrophobic and hydrophilic environments of the cell? A) Collagen fibers B) Proteoglycan complexes C) Integrins D) Plasmodesmata E) Glycoproteins

C) Integrins

Which of the following molecules have hydrophobic and hydrophilic components? A) Steroid B) Glycogen C) Phospholipid D) Protein E) Triglyceride

C) Phospholipid

The formation of a peptide bond involves A) release of nitrogen B) addition of nitrogen C) dehydration synthesis D) condensation reaction E) an increase in energy

C) dehydration synthesis

A cell with a cytoplasmic solute concentration that is lower than its environment is said to be A) hydrophilic B) hypertonic C) hypotonic D) isotonic E) isomorphic

C) hypotonic

Chargaff is credited with determining the base pairing rules as they relate to the structure of DNA. Which of the following explanations is accurate regarding the structure of DNA? (A) Uracil bonds covalently with adenine. (B) Pyrimidines bond with pyrimidines. (C) Purines form ionic bonds with pyrimidines. (D) Adenine hydrogen bonds with thymine. (E) Guanine bonds covalently with cytosine.

D Adenine hydrogen bonds with thymine.

17. The two strands of the spiral helix of DNA are held together by (a) ionic bonds (b) covalent bonds (c) peptide bonds (d) hydrogen bonds (e) cohesion

D Hydrogen bonds (2 between A&T, 3 between G&C) hold the two halves of DNA together.

14. Cholesterol is important in the metabolism of living things because it can be changed into important compounds that include all of the following EXCEPT (A) Vitamin D (B) bile salts (C) estrogen (D) keratin (E) testosterone

D Keratin is a protein. Remember many non-enzymatic proteins end with

2. Phospholipids naturally form a bilayer in water because of I. acidic reactions between lipid chains and water II. dipole interactions between phosphate groups and water III. hydrophobic interactions between lipid chains A) I only B) III only C) I and III only D) II and III only E) I, II and III

D) II and III only

Which organisms are responsible for converting nitrogen (N2) and hydrogen (H2) into ammonia (NH3)? A) Nitrifying bacteria B) Denitrifying bacteria C) Decomposing bacteria D) Nitrogen-fixing bacteria E) Aerobic fungi

D) Nitrogen-fixing bacteria

4. The process/reaction used to link compounds/monomers together. Releases water.

Dehydration

The diagram shows a bond forming between two amino acids. What is the name of this reciprocation?

Dehydration Synthesis

Which of the following statements is/are true with regard to a polymer of 6 glucose molecules? I. The chemical formula is C36H72O36 II. The chemical formula is C36H62O31 III. The monomers of glucose were joined via hydrolysis IV. The monomers of glucose were joined via dehydration synthesis (A) I only (B) II only (C) IV only (D) I and III only (E) II and IV only

E 6 glucose molecules will form 5 bonds. Each bond represents the subtraction of 2H and 1O due to dehydration synthesis. C36H72O36 - 10H and 5O = C36H62O31.

I. NAD+ II. ATP III. Uracil IV. Thymine 20. Which of the compounds is/are a component of DNA molecules? (A) I and II (B) III only (C) I and III (D) III only (E) IV only

E ATP can become a component of DNA when phosphates are removed. Only Thymine is a component of DNA.

10. A folded, coiled macromolecule that consists of one or more polypeptide chains describes a (A) phospholipid molecule (B) triacylglycerol molecule (C) glycogen molecule (D) cholesterol molecule (E) protein molecule

E Peptide bonds are found only in proteins.

Which of the following statements regarding lipids is most accurate? (A) Lipids are synthesized by ribosomes. (B) The empirical formula for lipids is typically C1H2O1. (C) Saturated fats tend to be solid at room temperature because of polar hydrocarbon chains. (D) Saturated fats tend to be liquid at room temperature due to hydrogen bonding. (E) Polyunsaturated fats tend to be liquid at room temperature due to numerous double bonds in the hydrocarbon chains.

E Polyunsaturated fats contain numerous double bonds making them liquid at room temperature.

DNA codes for 20 different amino acids. Which of the following is responsible for making each of the amino acids unique from one another (A) hydroxyl group (B) sulfhydryl group (C) amino group (D) methyl group (E) "R" group

E The R group is the only unique portion from one amino acid to another.

When attached to organic molecules, all of the following functional groups are hydrophilic and polar EXCEPT A) Carboxyl group B) Carbonyl group C) Amino group D) Phosphate group E) Methyl group

E) Methyl group

In an experiment a drop of leaf extract containing five components was placed near the bottom of a chromatography paper. Which of the following statements is NOT true? A) In the next step of the experiment the paper should be placed in a solvent which moves up the paper by capillary action. B) As the solvent touches the extract, each component within the extract moves at a different rate. C) In the end, five spots should appear on the paper. D) Pigments move at different rates according to their ability to dissolve in the solvent. E) The pigment that dissolves the best moves up the paper the slowest.

E) The pigment that dissolves the best moves up the paper the slowest.

Which of the following types of bonds would not be used to bind a substrate molecule to the active site of an enzyme? A) hydrogen bond B) ionic bond C) van der Waals interactions D) hydrophobic interactions E) peptide bonds

E) peptide bonds

2. Combines with 3 fatty acid chains to make up a triglyceride; part of the monomer of lipids

Glycerol

26. The lower the pH, the greater the concentration of :

H+

Hydrogen bonds occur (A) between nonpolar substances (B) between adenine and thymine (C) between phosphate and deoxyribose in DNA (D) when a hydrogen and an oxygen in a water molecule share electrons (E) between carbon and hydrogen in a molecule of methane

Hydrogen bonds occur between complementary base pairs. Answer choice D is describing a covalent bond

The secondary structure of a polypeptide is primarily determined by which of the following? (A) Hydrogen bonding (B) The number of amino acids (C) NADH (D) Golgi apparatus (E) Ribosomes

Hydrogen bonds stabilize the secondary structure.

. The process used to split polymers; this is done by adding water

Hydrolysis

3. The monomer, building block, of DNA and RNA; made up of a sugar, phosphate, and nitrogenous base

Nucleotide

17. The bond that joins amino acids are called:

Peptide Bonds

20. Why do lipids provide longer lasting energy than Carbohydrates?

They have many more C-H bonds

Which of the following terms refers to the loss of water in leaves through stomata to the atmosphere by evaporation? A) Absorption B) Anchorage C) Transpiration D) Storage E) Transport

Transpiration

27. This indicates an acidic substance:

[H+]>[OH-]

Which of the following is not a property of carbon? a. carbon to carbon bonds are limited to single bonds b. carbon has four valence electrons c. carbon can form bonds to various other atoms d. carbon to carbon bonds are strong

a

the products ot the process (hydrolysis) in the figure above are: a. monosaccharides b. molecules of glycerol c. representative of glycosidic linkage d. enzymes

a

1. The energy needed to start a reaction

activation energy

8. Where do substrates bind on an enzyme?

active site

a molecule of a saturated triacylglycerol (triglyceride) contains: a. the max number of double bonds between carbons in the fatty acid chains b. the max number of triple bonds between carbons in the fatty acid chains c. the max number of H atoms in the fatty acid chains d. alternating single and double bonds between carbons in the fatty acid chains

c

carbohydrate molecules: a. serve as structural components of human cell walls b. form the regulatory compounds known as enzymes c. are a source of energy d. help protect vital organs from damage

c

in which of the following reactions must the equivalent of a water molecule be added in order to break a bond? a. fatty acids + glycerol ---> fat b. glucose + fructose ---> sucrose c. glycogen ---> glucose alanine + glycine ----> dipeptide

c

. All organic compounds contain the element

carbon

7. What is a substance called if it speeds up a chemical reaction?

catalyst

12. Which property makes water molecules stick to other water molecules?

cohesion

which of the following illustrates hydrolysis? a. the reaction of two monosaccharides to form a disaccharide b. the reaction of two amino acids to form a dipeptide c. the reaction of a hydrogen atom and a hydroxide ion to form water d. the reaction of a fat to form glycerol and fatty acids

d

10. Changes in pH and temperature can damage an enzymes active site. What is this called?

denature

If someone is lactose intolerant, they lack the enzyme _____.

lactase

16. Is this hydrocarbon saturated or unsaturated?

saturated

21. Alpha helix and beta pleated sheets are part of what level of protein structure?

secondary

6. Which of the following is not a job of a protein

store and transmit genetic information

30. Which level of protein structure detremines the function of a protein?

tertiary