BIO131 #1

substrate

(1) A reactant that interacts with an enzyme in a chemical reaction. (2) A surface on which a cell or organism sits.

catalyst

(verb: catalyze) Acceleration of the rate of a chemical reaction due to a decrease in the free energy of the transition state, called the activation energy

catalysis

(verb: catalyze) Acceleration of the rate of a chemical reaction due to a decrease in the free energy of the transition state, called the activation energy.

polymerization

(verb:polymerize) The process by which many identical or similar small molcules (monomers) are covalently bonded to form a large molecule (polymer).

beta sheet

, ).is a stretch of amino acids typically 5-10 amino acids long whose peptide backbones are almost fully extended. The association of beta sheets has been implicated in the formation of protein aggregates and fibrils observed in many human diseases, notably the amyloidoses.

Cholesterol

-most common steroid in humans -precursor to steroid hormones, such as reproductive hormones -mostly insoluble in water -found in bile

10.3 The Calvin Cycle uses the chemical energy of ATP and NADPH to reduce CO2 to sugar

...

Describe a chlorophyll molecule

...

Photosynthesis converts light energy to the chemical energy of food

...

RNA

1 gene to make into proteins ribosome translation urical 3 types of RNA single strand

DNA

1 type of DNA double helix genes thymine transcription hydrogen bond deoxyribosome nucleus

What charge does the amino end of a polypeptide chain have? What charge does the free carboxyl group have?

1) a positive charge 2) a negative charge

The structure of an amino acid is composed of what 3 chemical groups? Of those 3 groups, which one is different from amino acid to amino acid?

1) carboxyl group 2) amino group 3) R group the R group is different from amino acid to amino acid

What different functions do proteins have?

1) structural support 2) storage 3) transport 4) movement 5) defense against foreign bodies 6) enzymes that speed up reactions

What is different between fats and phospholipids

1. phospholipids have only 2 fatty acid tails instead of 3 2. phospholipids have a polar group 3. phospholipids usually have at least one unsaturated bond

Oligosaccharides

10 to 20 sugars

Carbohydrates follow what formula?

1:2:1 for C:H:O

How many amino acids are there on Earth?

20

How many different kinds of amino acids are there in most proteins?

20

Proteins is built up of how many different Amino Acid

20 different Amino Acids composed of only C,H,O,N,S. The part of Amino Acid with different functional groups is Called R Group

-OH3 is at what end of a nucleic acid

3'

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; Adenine pairs with thymine and guanine pairs with cytosine.

Tertiary

3D, functional form

A phosphate group contains _________ oxygen atoms.

4

What do steroids look like

4 carbon rings

-PO4 is at what end of a nucleic acid

5'

base sequence that could form a short stretch of a normal double helix of DNA

5´-ATGC-3´ with 5´-GCAT-3´

Which of the following equations represents photosynthesis? 6CO2 + 6O2 → C6H12O6 + 6H2O 6H2O + 6O2 → C6H12O6 + 6CO2 C6H12O6 + 6O2 → 6CO2 + 6H2O C6H12O6 + 6CO2 → 6O2 + 6H2O 6CO2 + 6H2O → C6H12O6 + 6O2

6CO2 + 6H2O → C6H12O6 + 6O2 Photosynthesis requires carbon dioxide and water for the production of sugar and oxygen.

Na+/K+ Pump

7-% of energy from Glucose in the Brain is used to fuel the pump

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

75; 100 nucleotide pairs are a total of 200 nucleotides. Because of base pairing, if there are 25 adenine there must also be 25 thymine. This leaves 200-50 = 150 nucleotides to be divided evenly between guanine and cytosine.

A food company hydrogenates a barrel of fat. The treatment... A. made the fat less fluid B. made the fat less saturated C. lengthened the fat tails D. put more bends (kinks) in the fat tails E. both A and D

A

DNA and mRNA differ with respect to ... A. the kind of sugar they contain. B. the kinds of purines they contain. C. how many kinds of nucleotides are used to make the polymer. D. Both (a) and (b). E. the ability to make a double helix.

A

For good health, you don't want your body to run the LDL part of this diagram faster than the HDL part because... A. LDL cholesterol is stored; HDL cholesterol is destroyed. B. most of the body's cholesterol is built in the muscles. C. HDL lipoproteins carry less fat than LDL lipoproteins. D. muscles deteriorate if they store too much fat. E. LDL lipoproteins carry cholesterol; HDL lipoproteins do not.

A

Identify three possible components of a DNA nucleotide. A. deoxyribose, phosphate group, thymine B. adenine, phosphate group, ribose C. guanine, phosphate group, ribose D. cytidine, phosphate group, ribose E. deoxyribose, phosphate group, uracil F. cytosine, phosphate group, ribose

A

The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions? A. C60H102O51 B. C60H120O60 C. C6H12O6 D. C60H100O50 E. C60H111O51

A

What do the three main forces that stabilize protein tertiary structure have in common? A. They involve the side chains. B. They involve the water around the protein. C. They are weaker than covalent bonds. D. Both A and B E. Both A and C

A

What structural difference accounts for the functional differences between starch and cellulose? A. Starch and cellulose differ in the glycosidic linkages between their glucose monomers. B. Starch is a polymer of glucose, whereas cellulose is a polymer of fructose. C. Starch can be digested by animal enzymes, whereas cellulose cannot.

A

Which complex carbohydrate contains only a 1,4 glycosidic linkages? A. amylrose B. amylopectin C. glycogen D. cellulose

A

Which linkage forms the backbone of a nucleic acid? A. A sugar-phosphate linkage B. A base-phosphate linkage C. A sugar-base linkage D. A sugar-base-phosphate linkag

A

Which lipid is most amphipathic? A. Phospholipid B. Wax C. Triglyceride D. Cholesterol E. Fat

A

Which molecule is a nucleotide? A. ATP B. Deoxyribose C. The amino acid glycine

A

Which of the choices below best explains why steak has so much protein? A. contractile proteins B. structural proteins C. storage of amino acids for later D. Transport proteins E. Defensive proteins

A

Which of the following is NOT true of protein quaternary structure? A. A single polypeptide may have quaternary structure. B. Hydrogen bonds may hold the polypeptides in contact. C. A quaternary protein cannot have fewer than two carboxyl groups.

A

Which of the following statements about DNA structure is true? A. The nucleic acid strands in a DNA molecule are oriented antiparallel to each other. B. Phosphodiester bonds form between the phosphate group of one nucleotide and the 5' carbon of the adjacent nucleotide. C. The arrangement of the sugar-phosphate groups determines the genetic code. D. DNA is always synthesized in the 3' to 5' directio

A

Which of the following statements concerning unsaturated fats is true? A. They have double bonds in the carbon chains of their fatty acids. B. They are more common in animals than in plants. C. They have fewer fatty acid molecules per fat molecule. D. They contain more hydrogen than do saturated fats having the same number of carbon atoms. E. They generally solidify at room temperature.

A

Which of these is a source of lactose? A. milk B. sugar beets C. potatoes D. starch E. sugar cane

A

Which structure is not a component of a nucleotide? A. Sulfhydryl Oxygen group B. Nitrogen-containing base C. Phosphate group D. Pentose

A

glucose + glucose ---- ____ by ___ A. maltose + water....dehydration synthesis B. starch + water...dehydration synthesis C. cellulose + water... hydrolysis D. lactose + water...hydrolysis E. sucrose + water...dehydration synthesis

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.

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. A hydroxyl group is removed from the carboxyl group of one amino acid and hydrogen is removed from the amino group of the other amino acid, allowing a bond to form between the two groups.

oligopeptide

A chain composed of fewer than 50 amino acids linked together by peptide bonds. Often referred to simply as peptide.

polypeptide

A chain of 50 or more amino acids linked together by peptide bonds. Compare with oligopeptide and protein.

Antiparallel

A characteristic of the DNA double helix; one strand runs in the 5' to 3' direction while the other runs 3' to 5'

hydrolysis

A chemical reaction in which a molecule is split into smaller molecules by reacting with water. In biology, most hydrolysis reactions involve the splitting of polymers into monomers. Compare with condensation reaction.

condensation reaction

A chemical reaction in which two molecules are joined covalently with the removal of an -OH from one and an -H from another to form water. Also called a dehydration reaction. Compare with hydrolysis.

Reaction-center complex

A complex of proteins associated with a special pair of chlorophyll a molecules and a primary electron acceptor. Located centrally in a photosystem, this complex triggers the light reactions of photosynthesis. Excited by light energy, the pair of chlorophylls donates an electron to the primary electron acceptor, which passes an electron to an electron transport chain.

Light harvesting complex

A complex of proteins associated with pigment molecules (including chlorophyll a, chlorophyll b, and carotenoids) that captures light energy and transfers it to reaction-center pigments in a photosystem.

disulfide bond

A covalent bond between two sulfur atoms, typically in the side groups of some amino acids (e.g., cysteine). Often contributes to tertiary structure of proteins.

Two monosaccharides

A disaccharide

Thylakoids

A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy.

Thylakoids

A flattened, membranous sac inside a chloroplast. Thylakoids often exist in stacks called grana that are interconnected; their membranes contain molecular "machinery" used to convert light energy to chemical energy.

E

A function of cholesterol that does not harm health is its role _____. A. All of cholesterol's effects cause the body harm. B. as the primary female sex hormone C. in calcium and phosphate metabolism D. the most abundant male sex hormone E. as a component of animal cell membranes

Chlorophyll

A green pigment located in membranes within the chloroplasts of plants and algae and in the membranes of certain prokaryotes. Chlorophyll a participates directly in the light reactions, which convert solar energy to chemical energy.

multienzyme complex

A group of enzymes that are physically attached to each other, even though each of the enzymes catalyzes a separate? but usually related? chemical reaction.

transition state

A high-energy intermediate state of the reactants during a chemical reaction that must be achieved for the reaction to proceed. See activation energy.

prebiotic soup

A hypothetical solution of sugars, amino acids, nitrogenous bases, and other building blocks of larger molecules that may have formed in shallow waters or deep-ocean vents of ancient Earth and given rise to larger biological molecules.

Photosystem I

A light-capturing unit in a chloroplast's thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P700 chlorophyll a at its reaction center.

Photosystem

A light-capturing unit located in the thylakoid membrane of the chloroplast or in the membrane of some prokaryotes, consisting of a reaction-center complex surrounded by numerous light-harvesting complexes. There are two types of photosystems, I and II; they absorb light best at different wavelengths.

Exocytosis

A membranous vesicle is fusing with the plasma membrance and releasing its contents into the extracellular fluid

Photorespiration

A metabolic pathway that consumes oxygen and ATP, releases carbon dioxide, and decreases photosynthetic output. Photorespiration generally occurs on hot, dry, bright days, when stomata close and the O2/CO2 ratio in the leaf increases, favoring the binding of O2 rather than CO2 by rubisco.

cofactor

A metal ion or small organic compound that is required for an enzyme to function normally. May be bound tightly to an enzyme or associate with it transiently during catalysis.

A

A nucleotide is composed of a(n) _____. A. phosphate group, a nitrogen-containing base, and a five-carbon sugar B. glycerol, a nitrogen-containing base, and a five-carbon sugar C. amino group, a nitrogen-containing base, and a five-carbon sugar D. sulfhydryl group, a nitrogen-containing base, and a five-carbon sugar E. phosphate group, a nitrogen-containing base, and a hydrocarbon

C4 Plants

A plant in which the Calvin cycle is preceded by reactions that incorporate CO2 into a four-carbon compound, the end product of which supplies CO2 for the Calvin cycle.

CAM plants

A plant that uses crassulacean acid metabolism, an adaptation for photosynthesis in arid conditions. In this process, carbon dioxide entering open stomata during the night is converted to organic acids, which release CO2 for the Calvin cycle during the day, when stomata are closed.

C3 plants

A plant that uses the Calvin cycle for the initial steps that incorporate CO2 into organic material, forming a three-carbon compound as the first stable intermediate.

In a hydrolysis reaction; ___, and in this process water is ___.

A polymer is broken up into its constituent monomers...consumed

enzyme

A protein catalyst used by living organisms to speed up and control biological reactions.

α-helix (alpha-helix)

A protein secondary structure in which the polypeptide backbone coils into a spiral shape stabilized by hydrogen bonds between atoms.

β-pleated sheet (beta-pleated sheet)

A protein secondary structure in which the polypeptide backbone folds into a sheetlike shape stabilized by hydrogen bonding.

molecular chaperone

A protein that facilitates the three-dimensional folding of newly synthesized proteins, usually by an ATP-dependent mechanism.

The orange unit with two linked rings in this diagram represents

A purine. Purines have two linked rings.

monomer

A small molecule that can covalently bind to other similar molecules to form a larger macromolecule. Compare with polymer.

coenzyme

A small organic molecule that is a required cofactor for an enzyme-catalyzed reaction. Often donates or receives electrons or functional groups during the reaction.

amino acid

A small organic molecule with a central carbon atom bonded to an amino group (-NH3), a carboxyl group (-COOH), a hydrogen atom, and a side group. Proteins are polymers of 20 common amino acids.

Function of a protein is dependent on:

A specific recognition and binding

alpha helix

A spiral shape constituting one form of the secondary structure of proteins, arising from a specific hydrogen-bonding structure.

Glyceraldehyde 3-phosphate (G3P)

A three-carbon carbohydrate that is the direct product of the Calvin cycle; it is also an intermediate in glycolysis.

van der Waals interactions

A weak electrical attraction between two hydrophobic side chains. Often contributes to tertiary structure in proteins.

Which of the following molecules is a carbohydrate? A.) C50 H100 O50 B.) C51 H98 O6 C.) C22 H49 O10N5 D.) C45 H84 O8P4

A.) C50 H100 O50

Starch falls in what category? A.) Carbs B.) Proteins C.) Lipids D.) Nucleic acids

A.) Carbs

Generally, animals cannot digest the linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass? A.) Microorganisms in their digestive tracts hydrolyze the cellulose to glucose. B.) They have to eat a lot of grass. C.) Cows make an enzyme in their saliva that hydrolyzes cellulose. D.) Cows and other herbivores are exceptions and make some cellulose-digesting enzymes in their digestive tracts.

A.) Microorganisms in their digestive tracts hydrolyze the cellulose to glucose.

When three phosphate groups are covalently attached to adenosine, __________ is formed.

ATP

What two molecules are produced by the light reactions and used to power the Calvin cycle? CO2 and O2 C6H12O6 and O2 C6H12O6 and RuBP ATP and NADPH G3P and H2O

ATP and NADPH ATP and NADPH are both products of the light reactions and are used to power the Calvin cycle.

The light reactions of photosynthesis supply the Calvin cycle with

ATP and NADPH.

What is ATP's importance in the cell?

ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes.

How are proteins classed

According to shape and solubility

Which of DNA bases are purines?

Adenine and Guanine?

Nitrogenous bases are classified as either purines or pyrimidines. Examples of purines are __________.

Adenine and guanine

What are DNA bases?

Adenine, Guanine, Thymine, and Cytosine

What are RNA bases?

Adenine, Guanine, and Uracil

Name two monosaccharides?

Aldose and Ketose

What do Alzheimer's, Parkinson's, and mad cow disease have in common?( Concept 5.4)

All have been associated with the buildup of misfolded proteins in cells.

What do Alzheimer's, Parkinson's, and mad cow disease have in common?(eText Concept 5.4) * They all cause the misfolding of nucleic acids. * All are associated with the buildup of lipids in brain cells due to faulty lysosome activity. * All have been associated with the buildup of misfolded proteins in cells. * They all associated with plaque buildup in arteries (atherosclerosis). * All are caused by the buildup of misfolded proteins in cells.

All have been associated with the buildup of misfolded proteins in cells.

Enzyme molecules require a specific shape to perform their catalytic function. Which of the following might alter the shape of an enzymatic protein?

All of the listed responses are correct

Enzyme molecules require a specific shape to perform their catalytic function. Which of the following might alter the shape of an enzymatic protein? (eText Concept 5.4) * mixing in a chemical that removes hydrogen bonds * a change in salt concentrations or pH * heating the protein * denaturing the protein * All of the listed responses are correct.

All of the listed responses are correct. Correct. All of the listed responses would affect the shape and therefore the catalytic activity of the enzymatic protein.

hydrogen

Along the alpha helix, there is _______ bonding between the carbonyl oxygen of the backbone with the backbone nitrogen of the residue that is four positions ahead.

hydroxyl group of carbon-1 is below the plane of ring

Alpha

secondary

Alpha helices and beta pleated sheets are characteristic of a protein's ____________ structure.

protein's secondary structure.

Alpha helices and beta pleated sheets are characteristic of a protein's secondary structure

Which of these illustrates the secondary structure of a protein?

Alpha helices and beta pleated sheets are characteristic of a protein's secondary structure.

Fibrous proteins

Alpha helics & Beta (pleated) sheets

What are the two principle structures found in secondary proteins?

Alpha helix and Beta pleated strand

alpha beta glucose

Alpha: hydroxyl group of carbon-1 is below the plane of ring Beta: hydroxyl group of carbon-1 is above the ring

Which of the following is true regarding complementary base pairing in DNA and RNA molecules?

Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules.

Which of the following is true regarding complementary base pairing in DNA and RNA molecules? (Concept 5.5)

Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules.

Which of the following is true regarding complementary base pairing in DNA and RNA molecules? (eText Concept 5.5) * Complementary base pairing within single strands of DNA and RNA gives them particular three-dimensional structures that are necessary for their function. * Complementary base pairing promotes an antiparallel orientation in the structure of DNA and RNA molecules. * Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules. * Although a DNA molecule demonstrates complementary base pairing between two DNA polynucleotides to form a double helix, an RNA molecule can only base pair along stretches of nucleotides in the same RNA molecule, such as in transfer RNA molecules. * None of the listed responses is correct

Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules.

Proteins are Polymers of?

Amino Acids

Primary structure

Amino acid sequence

To what does the term polypeptide specifically refer?

Amino acids linked by dehydration synthesis

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

Amylose

Carotenoids

An accessory pigment, either yellow or orange, in the chloroplasts of plants and in some prokaryotes. By absorbing wavelengths of light that chlorophyll cannot, carotenoids broaden the spectrum of colors that can drive photosynthesis.

proline

An amino acid that causes kinks/bends in protein structures.

What connects the two photosystems in the light reactions? Chlorophyll A thylakoid An electron transport chain A chain of glucose molecules The Calvin cycle

An electron transport chain

PEP carboxylase

An enzyme that adds CO2 to phosphoenolpyruvate (PEP) to form oxaloacetate in mesophyll cells of C4 plants. It acts prior to photosynthesis.

Coagulation

An extreme case of Denaturation, which specifically refers to Solidification of Proteins. It is IRREVERSIBLE

prion

An infectious form of a protein that is thought to cause disease by inducing the normal form to assume an abnormal three-dimensional structure. Cause of spongiform encephalopathies, such as mad cow disease.

Heterotrophs

An organism that obtains organic food molecules by eating other organisms or substances derived from them.

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

An oxygen

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

An oxygen. The central carbon atom in an amino acid is bonded to an amino functional group, a carboxyl functional group, a side chain, and hydrogen.

Some athletes use anabolic steroids to build their body mass. Why is this considered a problematic practice, especially in adolescents?

Anabolic steroids can prevent bone growth.

polymer

Any long molecule composed of small repeating units (monomers) bonded together. The main biological polymers are proteins, nucleic acids, and polysaccharides.

myosin

Any one of a class of motor proteins that use the chemical energy of ATP to move along actin filaments in muscle contraction, cytokinesis, and vesicle transport.

macromolecule

Any very large organic molecule, usually made up of smaller molecules (monomers) joined together into a polymer. The main biological macromolecules are proteins, nucleic acids, and polysaccharides.

Proteins

Are Polymers of subunits known as AMINO ACID

Which of the following statements is a correct distinction between autotrophs and heterotrophs? Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. Only heterotrophs require oxygen. Cellular respiration is unique to heterotrophs. Only heterotrophs have mitochondria. Only heterotrophs require chemical compounds from the environment.

Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic.

Among the forces that stabilize protein tertiary structure, hydrogen bonds are especially important because they are ... A. more resistant to environmental disturbance than other forces. B. more numerous than the other forces. C. less associated with the backbone than the other forces. D. stronger than the other forces. E. more associated with side chains than the other forces.

B

Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? A. All bases would be separated from the deoxyribose sugars. B.The phosphodiester linkages of the polynucleotide backbone would be broken. C. The pyrimidines would be separated from the deoxyribose sugars. D. The two strands of the double helix would separate. E. The purines would be separated from the deoxyribose sugars.

B

Glycogen A. contains several kinds of sugars B. occurs in animal cells and has branches C. occurs in chloroplasts and stores energy D. is stronger, weight for weight, than steel E. none of the above

B

If you measure the amounts of the bases in any sample of DNA, you'll find that ... A. the amount of A + the amount of C = the amount of G + the amount of U. B. the amount of A + the amount of G = the amount of T + the amount of C. C. the amount of A = the amount of G; the amount of T = the amount of C. D. the amount of A + the amount of T = the amount of G + the amount of C. E. None of the above.

B

In a protein, peptide bonds connect ... A. C-R to N-H. B. C=O to N-H. C. C=O to C-R. D. N-H to C-H. E. All the above.

B

In fat synthesis, ______ and fatty acids combine to make fats plus _____ A. esters;phosphate B. glycerol; water C. esters;water D. phosphate; glycerol E. glucose; phosphate

B

Phospholipids are most important for... A. storing energy B. preventing leakage from cells C. lubricating cells D. waterproofing cell walls e. stiffening cells

B

Proteins are polymers of _____. A. nucleotides B. amino acids C. glycerol D. CH2O units E. hydrocarbons

B

RNA nucleotides contain __________ than DNA nucleotides. A. less phosphorus B. more oxygen C. different purines D. less oxygen E. None of the above.

B

The helical foldings of proteins are stabilized mainly by bonds between ... A. water molecules. B. CO and NH. C. ionic groups. D. S and S. E. side chains.

B

The human myoglobin protein contains 153 amino acids. If you take one guess at the amino acid sequence, what is your chance of being right? A. One chance in 18^153. B. One chance in 20^153. C. One chance in 153^20. D. One chance in 153. E. One chance in 20x153.

B

What do fats, steroids and waxes have in common? A. moderate polarity B. low solubility in water C. they occur in membranes D. both A and C E. both B and C

B

What does cholesterol have in common with sex hormones? A. Fatty acids. B. Four linked rings. C. Ester linkages. D. Strong polarity. E. Causes heart disease.

B

What type of bond joins the monomers in a protein's primary structure? A. hydrogen B. peptide C. S - S D. hydrophobic E. ionic

B

When a protein has been unfolded enough to lose its function, the protein has been ... A. distempered. B. denatured. C. hydrolyzed. D. metastasized. E. None of the above.

B

Which feature of large biological molecules explains their great diversity? A. The diversity of elements found in large biological molecules B. The many ways that monomers of each class of biological molecule can be combined into polymers C. The many classes of large biological molecules

B

Which of the following is true of pleated sheet foldings within a polypeptide? A. Its loops are held in place mainly by disulfide bridges. B. They depend on regular occurrence of CO and NH. C. The side chains are parallel to the plane of the sheet. D. They are part of the polypeptide's quaternary structure. E. All the above.

B

Which of the following statements about nucleotide structure is false? A. The nitrogenous base is bonded to the sugar. B. The phosphate group is bonded to the nitrogenous base. C. The sugar is bonded to the phosphate group. D. The sugar can be either ribose or deoxyribose.

B

Which of these is a polysaccharide? A. galactose B. cellulose C. sucrose D. glucose E. lactose

B

Which of these is rich in unsaturated fats? A. beef fat B. olive oil C. lard D. a fat that is solid at room temperature E. butter

B

Which polysaccharide contains a modified monosaccharide? A. cellulose B. peptidoglycan C. starch D. glycogen

B

Which statement expresses a real difference between DNA and RNA? A. DNA can make a double helix; RNA cannot. B. DNA is much longer than RNA. C. DNA has more kinds of bases than RNA. D. Both A and B. E. A, B and C

B

Which statement is incorrect? A. complex sugars are carbohydrates B. all carbohydrates have the general formula C∙(H₂O)∙ C. simple sugars are carbohydrates D. simple sugars contain only carbon, oxygen, and hydrogen atom

B

Which statement is true of polymers? A. their synthesis generally consumers water B. they are always made of monomers C. they are always made by condensation reactions D. none of the above

B

____ is the most abundant organic compound Earth A. starch B. cellulose C. glucose D. lactose E. glycogen

B

Lactase falls in what category? A.) Carbs B.) Proteins C.) Lipids D.) Nucleic acids

B.) Proteins

What makes the alpha helix so stable?

Because of H-bonding between carboxyl oxygen and the N 4 amino acids away. This make a 180° H bond, which is very stable.

hydroxyl group of carbon-1 is above the ring?

Beta

Which of the following is found in all amino acids?

Both -COOH and -NH2

How are the amide or peptide bond planes usually joined?

By the tetrahedral bonds of the alpha carbon. This is also the only bond that you can twist

Amino acids are called "acids" because they ... A. contain amino groups in the backbone part. B. contain amino groups in the side chain part. C. contain carboxyl groups in the backbone part. D. act as acids when they are bound to proteins. E. contain carboxyl groups in the side chain part.

C

Cellulose is... A. the third most abundant organic compound in the world B. branching polymer C. made with glucose that has the beta ring form D. a component of crab shells E. all of the above

C

In a membrane, the ____ of the phospholipids in one monolayer face the ____ of the phospholipids in the other monolayer A. heads;heads B. heads; tails C. tails; tails D. sometimes A; sometimes c E. none of these; a membrane is a monolayer

C

In the reaction that builds a fat, ____ groups react with _____ groups A. phosphate; amino B. carboxyl; amino C. hydroxyl; carboxyl D. sulfhydryl; carboxyl E. hydroxyl; phosphate

C

The sequence of polar and nonpolar side chains has a strong effect on a protein's folding mainly because ... A. nonpolar side chains attract one another. B. nonpolar side chains repel water. C. water attracts polar but not nonpolar groups. D. water repels nonpolar side chains. E. polar side chains attract one another.

C

To make a disulfide bridge, it's necessary to ... A. remove two OH groups. B. perform a hydrolysis reaction. C. remove two H atoms. D. remove an H and an OH. E. None of the above.

C

What holds the strands of the DNA double helix together? A. Covalent bonds between A and T, and between C and G. B. Proteins that bind to DNA bases. C. Hydrogen bonds between purines and pyrimidines. D. Attractions between polar sugars. E. Attractions between the ionized phosphates.

C

What will probably be the effect on a protein if you replace the amino acid proline with the amino acid glycine (side chain -H) at several points? A. The altered protein will have fewer hydrogen bonds than before. B. The altered protein will have shorter helices than before. C. The altered protein will have longer helices than before. D. There will be less rotation around backbone bonds than before. E. The primary structure of the altered protein will be shorter than before.

C

Which fact results from the presence of both polar and nonpolar side chains in a protein? A. Proteins ionize when they are placed in water. B. Each protein has many functions. C. Water has a strong effect on tertiary structure. D. A protein's folding doesn't depend on the polarity of the environment. E. pH has a strong effect on secondary structure.

C

Which molecule is not a carbohydrate? A. glycogen B. cellulose C. lipid D. starch

C

Which monomers make up RNA? A. simple sugars B. polymers C. nucleotides D. amino acids

C

Which of the following categories includes all others in the list? A. monosaccharide B. disaccharide C. carbohydrate D. polysaccharide starch

C

Which of the following is not attached to the central carbon atom in an amino acid? A. an amino functional group B. a carboxyl functional group C. an oxygen D. a side chain

C

Which part of an amino acid is always acidic? A. amino functional group B. side chain C. carboxyl functional group D. none of the above

C

Which statement helps to explain how DNA stores hereditary information? A. DNA contains 20 kinds of amino acids. B. DNA is made from thousands of kinds of monomers. C. DNA contains four kinds of nitrogenous bases. D. DNA binds a master copy of each kind of protein. E. DNA is a self-replicating type of protein

C

Why don't cells rely more on disulfide bridges to stabilize the folding of proteins? A. Disulfide bridges can only occur just after proline in the amino acid sequence. B. Though strong, disulfide bridges put a strain on the backbone. C. They make the protein rigid. Many proteins change their shape as they work. D. There's no room for more disulfide bridges. Most proteins have many of them. E. Disulfide bridges are too weak. Proteins can get more stability from ionic forces.

C

What is a statement that helps most to explain why life is based on carbon compounds?

C-C bonds are as strong as C-O bonds.

carboxyl end

C-terminus

Cholesterol falls in what category? A.) Carbs B.) Proteins C.) Lipids D.) Nucleic acids

C.) Lipids

Which of these is found in amines? A.) R-OH B.) R-COOH C.) R-NH2 D.) R-COH

C.) R-NH2

Lactose is a disaccharide (two monosaccharides joined together). To metabolize lactose, individuals require an enzyme known as lactase. What is true about this reaction? A.) The reaction causes reactants to be formed. B.) The reaction dehydrates the sugar. C.) The reaction hydrolyzes the sugar. D.) The reaction causes bloating in individuals who have the enzyme.

C.) The reaction hydrolyzes the sugar.

Proteins are an important class of molecules because of the functions they perform. Proteins can _____. A.) form dietary fiber B.) form membrane bilayers C.) act as signal receptors to receive signals in cell communication D.) store genetic information

C.) act as signal receptors to receive signals in cell communication

Which of the following molecules is a monosaccharide? ( Concept 5.2)

C6H12O6

Which of the following molecules is a monosaccharide? (eText Concept 5.2) * C25H43O8 * C22H49O10N5 * C51H98O6 * C45H84O8PN * C6H12O6

C6H12O6 Correct. Monosaccharides have molecular formulas that are multiples of CH2O.

Carbonyl group?

C=O

Similarities of DNA and RNA

CH groups nucleic acids carry genetic material phosphate groups A, G, C lead to protein production nitrogenous bases pentose sugar

Denaturation and Renaturation of a Protein

Can occur by changes like Temperature, Ph and Salt

BLANK include sugars and their polymers.

Carbohydrates

BLANK serve as fuel and building material.

Carbohydrates

Three of the four classes of life's organic molecules are polymers, Name them.

Carbohydrates, Proteins, Nucleic acids

What are the three phases of The Calvin cycle?

Carbon Fixation Energy Consumption and Redox Release of G3P; Regeneration of RuBP

What provides the carbon atoms that are incorporated into sugar molecules in the Calvin cycle? Sucrose (C12H22O11) RuBP Carbon dioxide (CO2) Glucose (C6H12O6) G3P (C3H6O3)

Carbon dioxide (CO2) Carbon dioxide provides the carbon atoms that are incorporated into sugars in photosynthesis. Carbon dioxide initially combines with RuBP, and RuBP is regenerated to continue the Calvin cycle.

Life's most important Molecules

Carbon, Nitrogen, Oxygen, Hydrogen, Phosphate, and sulfer

What allows proteins to assume different shapes and impact many different chemical reactions?

Carbon. It can assume a tetrahedral shape because it has 4 electrons available for sharing and can share those with atoms such as H2, O2 (double bonds), and N2 (triple bonds.)

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

The chemical group that acts as an acid is the __________.

Carboxyl Group (-COOH)

Which part of an amino acid is always acidic?

Carboxyl functional group

Which part of an amino acid is always acidic?

Carboxyl functional group. The carboxyl group (COOH) contains two oxygen atoms that tend to pull electrons away from the hydrogen atom, so this group tends to lose a proton and is acidic.

COOH functional group is know as a..?

Carboxylic acid

BLANK is a major component of the tough wall of plant cells.

Cellulose

Plant cell walls consist mainly of _____.

Cellulose

Which of the following components of a tossed salad will pass through the human digestive tract and be digested the least?

Cellulose (in the lettuce) Cellulose contains glycosidic linkages that cannot be broken down by human digestive enzymes

Which of the following is a polymer?

Cellulose, a plant cell wall component

Which of the following is a polymer

Cellulose, a plant cell wall component The polysaccharide cellulose is a major componenet of plant cell walls. It is a polymer composed of many glucose monomers joined together by glycosidic linkages

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

Cellulose: structural component of plant cell walls

induced fit

Change in the shape of the active site of an enzyme, as the result of the initial weak binding of a substrate, so that it binds substrate more tightly.

Enzyme molecules require a specific shape to perform their catalytic function. What might alter the protein shape?

Changing the concentration of salt in the environment

Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form?

Chaperonins

Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form?

Chaperonins Chaperonins shield proteins from "bad influences" while they are folding into their functional forms.

What other polysaccharide is similar to cellulose?

Chitin

....They were crunchy because their exoskeletons contain the polysaccharide___.

Chitin Chitin is the structural polysaccharide found in arthropod exoskeletons

At a conference, the speaker's grand finale was sautéing mealworms (insect larvae) in butter and serving them to the audience. They were crunchy (like popcorn hulls) because their exoskeletons contain the polysaccharide __________.

Chititn

In which of the following organelles does photosynthesis take place? Chloroplast Mitochondrion Ribosome Central vacuole Nucleus

Chloroplast Chloroplasts use energy from light to transform carbon dioxide and water into sugar and oxygen.

What makes hormones?

Cholesterol

High cholesterol levels are considered a major risk factor for heart disease. If it is so bad for humans, why does the body make cholesterol in the first place?

Cholesterol is the basis for many important molecules such as sex hormones

High cholesterol levels are considered a major risk factor for heart disease. If it is so bad for humans, why does the body make cholesterol in the first place? ( Concept 5.3)

Cholesterol is the basis for many important molecules such as sex hormones.

High cholesterol levels are considered a major risk factor for heart disease. If it is so bad for humans, why does the body make cholesterol in the first place? (eText Concept 5.3) * Cholesterol aids in the formation of amino acids that are used to build proteins. * Cholesterol is an important energy storage molecule. * Cholesterol is an important constituent of nucleotides. * Cholesterol is not important for humans any more. It is a holdover from hunter-gatherer days when food was scarce. * Cholesterol is the basis for many important molecules such as sex hormones.

Cholesterol is the basis for many important molecules such as sex hormones. Correct. Cholesterol is the basis for many steroid molecules, including sex hormones.

Which of the following is false in respect to cells' chromosomes?

Chromosomes only appear as a cell is about to divide.

5.4 Angstroms

Complete turn in an alpha helix is

Which statement about the cytoskeleton is true?

Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm.

Membranes

Composed of Phospholipids and Proteins (mainly)

Glycoprotein

Composed of both Carbohydrate and a Protein

Isomers

Compounds that have the same molecular formulas but different three-dimensional structures.

The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a ___bond.

Covalent Monomers are joined together by a deydration reaction in which two molecules are covalently bonded to each other through the loss of a water molecule.

examples of pyrimidines

Cytosine, Thymine, Uracil

A certain protein is not very sensitive to pH. It may have many side chains with ________ groups. A. carboxyl B. amino C. -PO3H2 D. -CH2OH E. -NH2

D

A cotton shirt is chemically most similar to a... A. DNA double helix B. slice of ham C. part of butter D. sugar cube E. fingernail

D

Defensive proteins are manufactured by the _____ system. A. digestive B. nervous C. cardiovascular D. immune E. integumentary

D

Fats vary with respect to the number of... A. hydrocarbon tails B. C atoms in the tails C. double bonds in the tails D. both B and C E. all of the above

D

Glycogen is ____ A. the form in which plants store sugars B. a transport protein that carries oxygen C. a polysaccharide found in plant cell walls D. a polysaccharide found in animals E. a source of saturated fat

D

If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain? A. 150 B. 200 C. 50 D. 75 E. 25

D

If you were to analyze a DNA sample from a eukaryotic cell, you would find that: A. the number of purines equals the number of pyrimidines. B. the number of adenines equals the number of uracils. C. the number of guanines equals the number of cytosines. D. Both A and C E. A, B and C

D

Polymers that contain sugars... A. may store hereditary information B. may store energy C. may protect cells D. both B and C E. A, B and C

D

The amino acid lysine has an amino group in its side chain. In a protein, a scientist replaced every lysine with serine (side chain -CH2OH). The alteration made the protein's folding ... A. more sensitive to pH. B. more dependent on amino acid sequence. C. less sensitive to heat. D. less sensitive to pH. E. less dependent on hydrogen bonds.

D

The helical foldings in proteins ... A. are kept folded by base-pairing. B. are kept folded by forces between side chains on adjacent turns of the helix. C. are part of the protein's primary structure. D. are kept folded by hydrogen bonds. E. None of the above.

D

The organic molecule called DNA is an example of A. a monomer B. a protein C. a polymer made of amino acids D. a polymer made of nucleotides E. a polymer made of nucleotes

D

The presence of many C-C and C-H bonds causes fats to be... A. rich in energy B. insoluble in water C. low in energy D. both A and B E. both B and C

D

The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases. A. S—S bonds B. covalent bonds C. hydrophilic interactions D. hydrogen bonds E. ionic bonds

D

What is the complementary DNA sequence to 5' ATGCATGTCA 3'? A. 5' TACGTACAGT 3' B. 5' ATGCATGTCA 3' C. 5' ACTGTACGTA 3' D. 5' TGACATGCAT 3'

D

Which of the following complex carbohydrates is listed with its correct function? A. amylose: main component of plant starch B. chitin: constituent of bacterial cell walls C. starch: primary energy-storage molecule in animals D. cellulose: structural component of plant cell walls

D

Which of the following statements about monosaccharide structure is true? A. all monosaccharides contain carbon, hydrogen, oxygen, and nitrogen atoms B. aldoses and ketoses differ in the position of their hydroxyl groups C. a six-carbon sugar is called pentose D. monsaccharides can be classified according to the spatial arrangement of their atoms

D

Which of the following statements about the foundation of polypeptides from amino acids is true? A. polypeptides form by condensation or hydrolysis reactions B. the reaction occurs through the addition of a water molecule to amino acids C. a bond can form between any carbon and nitrogen atom in the amino acids being joined D. a bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid

D

Which of these is NOT a lipid? A. wax B. steroids C. cholesterol D. phospholipid E. RNA

D

Which polymers are composed of amino acids? A. monomers B. carbohydrates C. nucleic acids D. proteins

D

Which statement is true of nucleic acids? A. rRNA positions amino acids along mRNA. B. mRNA binds amino acids together to make proteins. C. mRNA is part of the ribosome. D. DNA carries information for making RNA. E. Both B and D.

D

Which statement is true of phospholipids? A. their synthesis uses fatty acids B. some of their tails have double bonds C. they all ionize D. all the above E. both A and B

D

Which statement is true of the most abundant molecules in the membrane? A. Hydrogen bonds between the tails block transport through the membrane. B. Water keeps them oriented in the membrane. C. They contain ionized phosphate groups. D. Both B and C. E. All of the above.

D

Which statement is true of the side chains that occur in proteins? A. Some of them contain only C and H. B. Some of them contain carboxyl groups. C. None of them join the backbone at more than one point. D. Both A and B E. All the above.

D

DNA falls in what category? A.) Carbs B.) Proteins C.) Lipids D.) Nucleic acids

D.) Nucleic acids

Which of the following components of a tossed salad will pass through the human digestive tract with the least digestion? A.) sugar (in the dressing) B.) oil (in the dressing) C.) starch (in the croutons) D.) cellulose (in the lettuce)

D.) cellulose (in the lettuce)

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture ____.

DNA

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture _____.

DNA

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture _____. ( Concept 5.5)

DNA

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture _____. (eText Concept 5.5) * proteins * DNA * sucrose * cellulose * fatty acids

DNA

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________.

DNA

A&T

DNA

deoxyribose, ribose, thymine, uracil

DNA and RNA have similar structures: a pentose sugar with a nitrogenous base and a phosphate group; they differ in the type of pentose sugar each possesses (DNA has _____________; RNA has _______) and in one base (DNA has ________; RNA has _______).

Which statement helps to explain how DNA stores hereditary information?

DNA contains four kinds of nitrogenous bases.

DNA and RNA differences

DNA has a double strand, RNA contains ribose sugar and uracil

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

DNA to RNA to protein

Proteins account for more than 50% of the BLANK of most cells.

DRY mass

What does "dehydration" mean? (I sure hope you know this.)

Dehydration means to take water out.

What is the process by which monomers are linked together to form polymers

Dehydration or condensation reactions When monomers are linked together to form a more complex polymer, a water molecule is removed by dehydration reactions

What is the process by which cells link monomers together to form polymers?

Dehydration reaction

What joins fatty acids to glycerol?

Dehydration synthesis

What name is given to the process seen in this animation?

Dehydration synthesis

When a peptide bond forms between the amino and carboxyl groups, what process does it go through?

Dehydration synthesis

When a protein is denatured, why does it lose its functionality? ( Concept 5.4)

Denaturation breaks the weak bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function.

When a protein is denatured, why does it lose its functionality? (eText Concept 5.4) * Denaturation destroys the primary structure of the protein, and the protein breaks down to monomers. * Different amino acids are substituted into the sequence, so the protein's properties change. * Denaturation breaks the weak bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function. * Denaturation breaks the covalent bonds that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function. * The protein's pH changes, causing it to lose its functionality.

Denaturation breaks the weak bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function.

When a protein is denatured why does it lose its functionality?

Denaturation breaks the weak bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function. Denaturation disrupts secondary, tertiary, and quaternary protein structure, causing the protein to lose its form and thus its function.

There are two types of nucleic acids - Name them.

Deoxyribonucleic acid (DNA), Ribonucleic acid (RNA)

Name the Basic Protein Separation/ Purification Strategies. How to they separate proteins?

Dialysis: separation by diffusion Affinity: separation by affinity. Antibodies are often used Size Exclusion: separation by size- Gel Filtration Chromatography Ion Exchange: separation based on charge. (Ion Exchange Chromatography) Hydrophobic Interaction: separation by hydrophobic tendencies Ultracentrifugation: separation by mass.

What Process occurs during osmosis?

Diffusion Osmosis is the diffusion of water across a selectively permeable membrane

BLANK provides directions for its own replication.

Dna

How does dehydration synthesis work in Lipids?

During the dehydration glycerol and fatty acid are joined, and water comes out as a result. The remaining chemicals bond (see image on handout for details).

A function of cholesterol that does not harm health is its role _____ A. the most abundant male sex hormone B. in calcium and phosphate metabolism C. as the primary female sex hormone D. all of cholesterol's effects cause the body harm E. as a component of animal cell membranes

E

A nucleotide is composed of a(n) _____. A. glycerol, a nitrogen-containing base, and a five-carbon sugar B. sulfhydryl group, a nitrogen-containing base, and a five-carbon sugar C. phosphate group, a nitrogen-containing base, and a hydrocarbon D. amino group, a nitrogen-containing base, and a five-carbon sugar E. phosphate group, a nitrogen-containing base, and a five-carbon sugar

E

Dr. Haxton told one of his students, "To move in the bloodstream fats need the help of phospholipids." What would a good student say? A. Sorry! Help comes from cholesterol, not phospholipids B. Right. Fats are too polar to travel alone in water C. Not so. Fats are small enough to travel easily without help D. You have it backwards. Fats help phospholipids to travel E. Yes. Nonpolar molecules aren't compatible with water

E

If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand? A. 3'-TUUUCG-5' B. 3'-ATTTGC-5' C. 3'-UAAACG-5' D. 3'-GCAAAT-5' E. 3'-TAAACG-5'

E

It is difficult for molecules to pass through the phospholipid bilayer because ... A. cholesterol holds phospholipids in place. B. hydrocarbons repel water. C. proteins hold phospholipids in place. D. there is a water film between the monolayers. E. polar molecules attract one another.

E

Some of the strongest biological structures (e.g., beaks and claws) are made of many molecules of the protein keratin. What else is true of structures made of keratin? A. Disulfide bridges bind the proteins together. B. Each protein is a single long alpha helix. C. Hair is another example. D. Both A and B E. A, B and C.

E

Tertiary structure is NOT directly dependent on _____. A. hydrogen bonds B. hydrophobic interactions C. bonds between sulfur atoms D. ionic bonds E. peptide bonds

E

The information in DNA tells a cell how to make ... A. proteins. B. DNA. C. tRNA. D. Both A and B. E. A, B and C

E

The most unsaturated fats have... A. the highest ration of H to C B. the fewest double bonds C. the shortest hydrocarbon tails D. the longest hydrocarbon tails E. the most double bonds

E

The secondary structure of a protein results from _____. A. hydrophobic interactions B. bonds between sulfur atoms C. ionic bonds D. peptide bonds E. hydrogen bonds

E

The structural level of a protein least affected by a disruption in hydrogen bonding is the A. tertiary level B. All structural levels are equally affected. C. quaternary level. D. secondary level. E. primary level.

E

To find the best source of phospholipids, look at... A. surfaces of leaves B. cell walls C. nasal mucus D. storage droplets E. membranes

E

What do DNA, proteins and fats have in common? A. they are polymers B. they are polar C. they contain nitrogen D. they contain phosphorus E. they contain carbonyl groups

E

What do phosphoglycerides and fats have in common? A. tendency to form bilayers B. a strongly polar group C. three fatty acid tails D. a role in membrane structure E. ester linkages

E

What fact is most important in causing phospholipids to behave as they do in water? A. nonpolar groups repel water B. hydrogen is more electronegative than oxygen C. hydrocarbons attract one another D. phosphate groups can bind together E. water molecules make hydrogen bonds

E

Which factor is most important in determining a protein's optimum pH? A. The sensitivity of hydrocarbon side chains to pH. B. The pH of the protein's environment. C. The number of backbone carboxyl groups. D. The number of amino groups in the protein's backbone. E. The locations of side-chain carboxyl groups

E

Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? A. All of these pairs are correct. B. 5´-GCGC-3´ with 5´-TATA-3' C. 5´-purine-pyrimidine-purine-pyrimidine-3´ with 3´-purine-pyrimidine-purine-pyrimidine-5´ D. 5´-AGCT-3´ with 5´-TCGA-3´ E. 5´-ATGC-3´ with 5´-GCAT-3´

E

Which of these does NOT contain a structural protein? A. ligaments B. spider silk C. tendons D. muscles E. ovalbumin

E

Amino groups ... A.) act as bases in water. B.) contain nitrogen atoms. C.) occur in proteins. D.) Just two of the preceding answers are true. E.) (a), (b), and (c).

E.) (a), (b), and (c).

Side Chain

Each of the 20 different Amino Acid has a unique Side Chain. The molecular structure of the side chain determines how the Amino Acid will interact with other Amino Acids in the chain an dhow it will interact with water

Why do orthologs have some regions of amino acids that are identical between species? Give an example

Either the sequence is structurally important for proteins to fold correctly or because it plays a very critical role in the function of the protein. Cytochrome C is a good example.

partial positive

Electronegative oxygen and nitrogen atoms leave hydrogen atoms with ________ __________ charges.

Carbohydrates are used in our bodies mainly for ___.

Energy storage and release Simple sugar molecules, stored in polysaccharides such as glycogen in animals and starch in plants, are a major energy source for cellular work

Phagocytosis

Englulfes of large particles

In terms of cellular function, what is the most important difference between prokaryotic and eukaryotic cells?

Eukaryotic cells are compartmentalized, which allows for specialization.

myoglobin, hemoglobin

Examples of a Alpha Helix

True or False: Different proteins never share common ancestors.

False. Evolutionary relatedness can be inferred from sequence homology.

Saturated fat

Fatty acids lack double bonds

Essential Fatty Acids

Fatty acids that are not synthesized by the body therefore must be consumed in the diet such as Omega-3 and Omega-6 fatty acids, in able to meet needs sufficiently.

Hydrogenated vegetable oils are more like animal fats than other plant oils. Because they (CONTAIN MORE OR FEWER DOUBLE BONDS) than other plant oils, they can contribute to cardiovascular disease.

Fewer

How is the sequence of amino acids read?

From the amino terminus to the carboxyl terminus.

What are two (optical) isomers of glucose, and have different properties?

Galactose and mannose

What two shapes can a protein be?

Globular and fibrous

BLANK (C6H12O6) is the most common monosaccharide.

Glucose

What is the main sugar used by cells for energy?

Glucose

Which of the following carbohydrate molecules has the lowest molecular weight?

Glucose

A polysaccharide that we use for storing energy in our muscles and livers is _____.

Glycogen

A polysaccharide that is used for storing energy in human muscle and liver cells is ___.

Glycogen Humans and other vertebrates store glucose as a polysaccharide called glycogen in their liver and muscle cells

C

Glycogen is _____. A. a source of saturated fat B. the form in which plants store sugars C. a polysaccharide found in animals D. a transport protein that carries oxygen E. a polysaccharide found in plant cell walls

In a basic solution, COOH will release what?

H+

What provides electrons for the light reactions? CO2 The Calvin cycle H2O Light O2

H2O Electrons are stripped from water in the light reactions of photosynthesis. Light provides the energy to excite electrons.

Which of the following sequences correctly represents the flow of electrons during photosynthesis? NADPH → chlorophyll → Calvin cycle H2O → NADPH → Calvin cycle NADPH → O2 → CO2 NADPH → electron transport chain → O2 H2O → photosystem I → photosystem II

H2O → NADPH → Calvin cycle

Hydroxyl group?

HO

Quaternary Structure Example

Hemoglobin

What can pass easily through the plasma membrane

Hydrocarbon, Oxygen and carbon dioxide

The Secondary Structure of a Protein results from what bond?

Hydrogen Bonds

What type of Bond is in the Secondary Structure?

Hydrogen Bonds

Teritary Structure is depenedent on what bond/interaction?

Hydrogen Bonds,Hydrophobic Interactions, Ionic Bonds, Bonds between Sulfur Atoms

Alpha Helix

Hydrogen bonds form between the C=O and -NH of the amino acids to form a spiral. Secondary structure of protein

The secondary structure of a protein results from

Hydrogen bonds. Electronegative oxygen and nitrogen atoms leave hydrogen atoms with partial positive charges.

When glycogen is converted into glucose, what process does it go through?

Hydrolysis

What is hydrolysis?

Hydrolysis is the separation of two macromolecules by adding water.

Which is the correct term for compounds that do not mix with water?

Hydrophobic

Which is the term for compounds that do not mix with water?

Hydrophobic

The fatty acid tails of a phospholipid are ___ because they ___.

Hydrophobic...have no charges to which water molecules can adhere

C

Identify three possible components of a DNA nucleotide. A. cytidine, phosphate group, ribose B. deoxyribose, phosphate group, uracil C. deoxyribose, phosphate group, thymine D. adenine, phosphate group, ribose E. guanine, phosphate group, ribose F. cytosine, phosphate group, ribose

E

If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain? A. 200 B. 150 C. 25 D. 50 E. 75

D

If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand? A. 3'-TUUUCG-5' B. 3'-UAAACG-5' C. 3'-ATTTGC-5' D. 3'-TAAACG-5' E. 3'-GCAAAT-5'

Defensive Proteins are manufactured by WHAT system?

Immune System

Bundle-sheath cells

In C4 plants, a type of photosynthetic cell arranged into tightly packed sheaths around the veins of a leaf.

Where can Structural Protein be Found?

In Muscle, Spider Silk, Tendons and Ligaments

A, T, G, C

In a DNA sequence, the purine ___ always pairs with the pyrimidine ___, and the purine ___ always pairs with the pyrimidine ___.

initiation

In an enzyme-catalyzed reaction, the stage during which enzymes orient reactants precisely as they bind at specific locations within the enzyme's active site.

How is photosynthesis similar in C4 plants and CAM plants?

In both cases, rubisco is not used to fix carbon initially.

How does dehydration synthesis work in carbohydrates?

In carbohydrates, an H from one simple sugar, and an OH from another are taken out, which will form water. The two simple sugars are then joined to form a carbohydrate!

termination

In enzyme-catalyzed reactions, the final stage in which the enzyme returns to its original conformation and products are released.

secondary structure

In proteins, localized folding of a polypeptide chain into regular structures (e.g., a-helix and b-pleated sheet) stabilized by hydrogen bonding between atoms of the backbone. In nucleic acids, elements of structure (e.g., helices and hairpins) stabilized by hydrogen bonding and other interactions between complementary bases. Compare with primary, tertiary, and quaternary structure.

Primary electron acceptor

In the thylakoid membrane of a chloroplast or in the membrane of some prokaryotes, a specialized molecule that shares the reaction-center complex with a pair of chlorophyll a molecules and that accepts an electron from them.

competitive inhibition

Inhibition of an enzyme's ability to catalyze a chemical reaction via a nonreactant molecule that competes with the substrate(s) for access to the active site.

hydrophilic

Interacting readily with water. Hydrophilic compounds are typically polar compounds containing charged or electronegative atoms. Compare with hydrophobic.

H-bonding Ionic Hydrophobic Van der Waals Covalent

Interactions that hold proteins together

Endocytosis moves materials.....a cell via.....? prefix (endo-inward)

Into.....Membraneous Vesicles

Avitve Transport

Is moving a substance AGAINST a Gradient so it needs Engergy (ATP) and a Trans-Membrane Protein

Enantiomer

Isomer molecules that are mirror images

How does this work?

It is essentially the exact opposite of dehydration synthesis.

3.6

It takes _______ residues to make a single turn in an alpha helix, so you can see how the residues would be aligned to allow this hydrogen-bonding.

Phospholipids

Like a triglyceride, a phospholipid has a backbone of glycerol, but it contains two fatty acids rather than three. Instead of the third fatty acid, a phospholipid has a chemical group containing phosphorus, called a phosphate group. The fatty acids at one end of a phospholipid molecule are soluble in fat, while the phosphate-containing region at the other end is soluble in water. Phospholipids act as emulsifiers because they can surround droplets of oil, allowing them to remain suspended in a watery environment. Phospholipids are an important component of cell membranes. They form a double-layered sheet called the lipid bilayer by orienting the water-soluble, phosphate containing "heads" toward the aqueous (water) environments inside and outside the cell and the fatty acid "tails" toward each other to form the lipid center of the membrane.

Which molecule is not a carbohydrate?

Lipid

Cholesterol belongs to which class of molecules?

Lipids

The sex hormones estrogen, progesterone, and testosterone belong to which class of molecules?

Lipids

How can a lipid be distinguished from a sugar?

Lipids are Non-Polar molecules and Sugars are Polar molecules

What is the defnition of a lipid?

Lipids are mostly NON-Polar

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

Low solubility in water

Polymers that contain sugars

May store hereditary information, energy and protect cells.

Generally, animals cannot digest (hydrolyze) the glycosidic linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass? ( Concept 5.2)

Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units.

Generally animals cannot digest the glycosidic linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass?

Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units. Cows have digestive chambers populated by microorganisms that can produce certain hydrolytic enzymes that cows cannot. The enzymes hydrolyze the cellulose polymer into glucose monomers

Generally, animals cannot digest (hydrolyze) the glycosidic linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass? (eText Concept 5.2) * Cows and other herbivores are exceptions and make some cellulose-digesting enzymes. * They have to eat a lot of it. * Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units. * The flat teeth and strong stomach of herbivores break the cellulose fibers so that the cows get enough nutrition from the cell contents. * All of the listed responses are correct.

Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units. Correct. Cows have digestive chambers populated by microorganisms that can produce certain hydrolytic enzymes that cows cannot. The enzymes hydrolyze (digest) the cellulose polymer into glucose monomers.

Enantiomers are

Mirror images

The endosymbiont theory explains the origins of __________.

Mitochodria and chloroplasts

Facilitated Diffusion

Molecules that are TOO large to fit through pores and are NOT soluble in lipids need transmembranse Protein (Glucose and Amino Acid)

BLANK are connected by covalent bonds that form through the loss of a water molecule. This reaction is called a condensation reaction or BLANK reaction.

Monomers, dehydration

A molecule with the chemical formula C6H12O6 is probably a _____.

Monosaccharide

BLANK have molecular formulas that are usually multiples of CH2O.

Monosaccharides

Which of the following statements about monosaccharide structure is true?

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

unsaturated

Most plant oils are rich in _____________ fats.

Cilia and flagella move due to the interaction of the cytoskeleton with which of the following?

Motor proteins

What is chitin made of and what type of bonds?

N-acetylglucosamine that also form hydrogen bonds

amino end

N-terminus

What transports electrons from the light reactions to the Calvin cycle? NADH NADPH An electron transport chain FADH2 Chlorophyll

NADPH NADPH is an electron carrier that picks up electrons in the light reactions and releases them in the Calvin cycle. An electron transport chain conveys electrons from one photosystem to the other within the light reactions.

What is a distinguishing feature of most naturally occuring fats?

Nearly all naturally occuing unsaturated fats have cis double bonds Naturally occuring unsaturated fats found in plants and fish are distinguished by the presence of one or more cis double bonds in their hydrocarbon chains

What is a distinguishing feature of most naturally occurring fats? ( Concept 5.3)

Nearly all naturally occurring unsaturated fats have cis double bonds.

What is a distinguishing feature of most naturally occurring fats? (eText Concept 5.3) * Nearly all naturally occurring unsaturated fats have cis double bonds. * Most unsaturated fats have trans double bonds, causing a kink in the hydrocarbon chain wherever they occur. * All organisms share an equal ratio of saturated and unsaturated fatty acids. * They all share four fused rings as a carbon skeleton. * They are distinguished from other lipid forms by their chief role as components of cell membranes. End of Question 20

Nearly all naturally occurring unsaturated fats have cis double bonds. No. Unsaturated fats with trans double bonds are formed in the industrial process of hydrogenating unsaturated plant oils.

NADP

Nicotinamide adenine dinucleotide phosphate, an electron acceptor that, as NADPH, temporarily stores energized electrons produced during the light reactions.

What is a key feature of omega-3 fatty acids that distinguishes them from other types of fatty acids? (Concept 5.3)

None of the listed responses correctly describes a distinguishing key feature of omega-3 fatty acids.

What is a key feature of omega-3 fatty acids that distinguishes them from other types of fatty acids? (eText Concept 5.3) * It is one of the only unsaturated fatty acids that is produced by humans. * Omega-3 fatty acids are distinguished by the presence of three trans double bonds in their hydrocarbon chain. * Omega-3 fatty acids are typically lacking in a vegetarian diet and must be provided by taking animal-derived supplements. * Like other saturated fatty acids, a diet rich in omega-3 fatty acids can promote plaque formation in the blood vessels. * None of the listed responses correctly describes a distinguishing key feature of omega-3 fatty acids

None of the listed responses correctly describes a distinguishing key feature of omega-3 fatty acids.

To what does the term "polypeptide" refer? (eText Concept 5.4) * organic molecules linked by dehydration reactions * carbohydrates with a hydrogen bond holding them together * amino acids linked by hydrolysis * organic monomers covalently bonded * None of the listed responses is correct.

None of the listed responses is correct

To what does the term "polypeptide" refer? ( Concept 5.4)

None of the listed responses is correct.

How likely is it that the next base, out of sight at the top of this polymer, is uracil?

Not a chance, since this is a DNA molecule, not an RNA molecule.

hydrophobic

Not interacting readily with wter. Hydrophobic compounds are typically nonpolar compounds that lack charged or electronegative atoms and often contain many C - C and C - H bonds. Compare with hydrophilic.

Which monomers make up RNA?

Nucleotides

What are two classes of fatty acids are essential in diet?

Omega 3: Alpha-linolenic acid Omega 6: Linoleic acid

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

On the inside of the folded chain, away from water

Pharmaceutical companies are selling close to $200 billion worth of single-enantiomer drugs. Why might it be important to use only one form of an enantiomer?

One enantiomer may provide an effective treatment whereas the other may be ineffective or even toxic.

globular

One of three protein structure: Proteins can also be_______, and this class of protein structure is the most common with soluble proteins, that is, proteins that exist free in the cytosol or other biological fluids.

purine

One of two families of nitrogenous bases found in nucleotides. Adenine (A) and guanine (G) are ______

Photo system II

One of two light-capturing units in a chloroplast's thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P680 chlorophyll a at its reaction center.

What particle could diffuse easily through a cell membrane?

Oxygen (o2)

Denaturation

PH, salt concentration, temperature or other environmental factors are ALTERED, the Protein unravels and loses its native conformation

Micelles

Particles that are formed in the small intestine when the products of fat digestion are surrounded by bile salts. They facilitate the absorption of lipids. In the small intestine, the products of fat digestion and bile form micelles, which move close enough to the brush border to allow lipids to diffuse into the mucosal cells.

What is a nucleotide?

Pentose sugar nitrogenous base phosphate group

The tertiary structure of a protein includes all of the following interactions except _________ bonds.

Peptide

What type of Bond joins the Monomers in a Protein's Primary Structure?

Peptide Bonds

Which polysaccharide contains a modified monosaccharide?

Peptidoglycan. The N-acetylglucosamine and N-acetylmuramic acid units that make up peptidoglycan are composed of modified glucose monomers.

A white blood cell englulfing a bacterium is an Example of?

Phagocytosis

Which functional group has the most different ionized forms?

Phosphate

Which of the following is a true statement comparing phospholipids and triacylglycerols (fats and oils)? ( Concept 5.3)

Phospholipid molecules have a distinctly polar "head" and a distinctly nonpolar "tail," whereas triacylglycerols are predominantly nonpolar.

Which of the following is a true statement comparing phospholipids and triacylglycerols (fats and oils)? (eText Concept 5.3) * Both molecules contain a phosphate group. * Phospholipids are the primary storage form for fats in our bodies. * Triacylglycerols may be saturated or unsaturated, but all phospholipids are saturated. * Phospholipid molecules have a distinctly polar "head" and a distinctly nonpolar "tail," whereas triacylglycerols are predominantly nonpolar. * In nature, phospholipids occur in fused rings (sterol form), whereas triacylglycerols maintain a straight-chain form.

Phospholipid molecules have a distinctly polar "head" and a distinctly nonpolar "tail," whereas triacylglycerols are predominantly nonpolar. Correct. Triacylglycerols consist of three (nonpolar) fatty acid tails attached to a glycerol molecule. Phospholipids have two fatty acid tails and a hydrophilic head containing a negatively charged phosphate group.

Which of the following is a true statement comparing phospholipids and triacylglycerols(fats and oils)?

Phospholipid molecules have a distinctly polar head and distinctly nonpolar tail, wheras tracylglycerols are predominantly nonpolar. Triacylglycerols consist of three (nonpolar) fatty acid tails attached to a glycerol molecule. Phospholipids have two fatty acid tails and a hydrophilic head containing a negatively charged phosphate group.

The lipids that form the main structural component of cell membranes are _____.

Phospholipids

The lipids that form the main structural component of cell membranes are ___.

Phospholipids Phospholipids have a hydrophilic head and two hydrophobic tails. This permits the phospholipids to be arranged in a bilayer, or double layer, which forms a boundary between the cell and its external environment.

Phospholipids bilayer of membrance consist of?

Phospholipids and can be recognized by the presence of a head and two tails

Phospholipid structure

Phospholipids are composed of a phosphate group, a glycerol, and fatty acids.

Phosphatidylcholine

Phospholipids undergo dehydration synthesis to join fatty acids, glycerol and polar head group

Cellulose is a __ made of many__.

Polymer...glucose molecules Cellulose is a polysaccharide and therefore a polymer, constructed from many monosaccharide glucose monomers.

Glycogen is a monosaccaride, disaccaride, or a polysaccaride?

Polysaccaride

BLANK are polymers of hundreds to thousands of monosaccharides joined by glycosidic linkages.

Polysaccharides

At what level of protein structure describes an AMino Acid sequence such as Ala-Gly-Ser-Val-Glu-Glu-Glu-Ala-His?

Primary Structure

Which of the following statements about the primary structure of a protein is true?

Primary structure is produced by the unique sequence of amino acids in a protein.

Primary Structure

Primary structure is the sequence of Amino Acids in a Protein

What are the four levels of protein structure?

Primary: sequence of amino acids Secondary: local structures- H-bonds Tertiary: overall 3-d shape Quaternary: subunit organization (two or more interacting polypeptide chains)

Renaturation

Protein MAY be able to return to its normal shape

Which of the following lists ranks these molecules in the correct order by size?

Protein, sucrose, glucose, water (largest to smallest)

Which polymers are composed of amino acids?

Proteins

A

Proteins are polymers of _____. A. amino acids B. hydrocarbons C. CH2O units D. glycerol E. nucleotides

Collagen is found in connective tissue, which is a structural component of bones, tendons, and ligament. Collagen has great strength because of its _____ structure.

Quaternary

Which level of the protein structure involves two or more polypeptide chains?

Quaternary

At what level of protein structure do the Alpha and Beta protein subunits come together to catalyze the HYDROLYSIS reaction

Quaternary Structure

Quaternary Structure

Quaternary Structure is the result of two or more protein subunits assemnling to form a larger, biologically active Protein Complex

Which level of protein structure is characteristic of some, but not all, proteins?

Quaternary level of protein structure

A&U

RNA

Which of these is NOT a lipid?

RNA

How does DNA differ from RNA?

RNA contains ribose, DNA does not.

Which of the following describes a difference between DNA and RNA? ( Concept 5.5)

RNA molecules consist of a single polynucleotide chain, whereas DNA molecules consist of two polynucleotide chains organized into a double helix; one of their nitrogenous bases is different; they contain different sugars

What are the some uses if the amino acid sequence of a protein?

Reflect the function of the protein. Reveal the domain structure: is it an alpha helix or beta pleated sheet? Where are the hydrophilic and hydrophobic regions? Reveal mosaicism in primary structures: it is possible to have a disparity in amino acids but still have the similar functions. Facilitate predictions on higher order of structures Facilitate construction of probes for genes Allow evaluation of relationships between proteins within a given species (paralogs) or between different species (orthologs).

allosteric regulation

Regulation of a protein's function by binding of a regulatory molecule, usually to a specific site distinct from the active site, causing a change in the protein's shape.

Which of the following is present in a prokaryotic cell?

Ribosomes

Which of the following groups is primarily involved in synthesizing molecules needed by the cell?

Ribosomes, rough endoplasmic reticulum, and smooth endoplasmic reticulum

How can you determine protein characterization?

SDS Polyacrylamide Gel Electrophoresis and Isoeletric focusing.

BLANK, the smallest carbohydrates, serve as fuel and a source of carbon.

SUGARS

Nutritionally, saturated triacylglycerols are considered to be less healthful than unsatruated tracylglycerols. What is the difference between them?

Saturated tracylglycerols have more hydrogen atoms than unsaturated tracylglycerols

Nutritionally, saturated triacylglycerols are considered to be less healthful than unsaturated triacylglycerols. What is the difference between them? ( Concept 5.3)

Saturated triacylglycerols have more hydrogen atoms than unsaturated triacylglycerols.

Nutritionally, saturated triacylglycerols are considered to be less healthful than unsaturated triacylglycerols. What is the difference between them? (eText Concept 5.3) * Saturated triacylglycerols have more double bonds than unsaturated triacylglycerols. * Saturated triacylglycerols have more hydrogen atoms than unsaturated triacylglycerols. * Saturated triacylglycerols are fats; unsaturated triacylglycerols are carbohydrates. * Saturated triacylglycerols are liquid at room temperature. * All of the listed responses are correct.

Saturated triacylglycerols have more hydrogen atoms than unsaturated triacylglycerols. Correct. Saturated triacylglycerols are saturated with hydrogen atoms

At what level of Protein structure do the chains of Amino Acids fold into an Alpha-Helical Structure?

Secondary Structure

Secondary Structure

Secondary Structure describes the Alpha Helices and Beta sheets that are formed by Hyrogen Bonding between backbone Atoms located near each other in the POLYPEPTIDE CHAIN

Rancidity

Spoilage of fats and oils. Occurs when oxygen damages the unsaturated bonds in fatty acids.

Cholesterol in a phospolipid bi-layer helps with?

Stabilization of the Phospholipids and Cholesterol helps to stabilize the structure of the plasma membrance

Glucose is the direct breakdown product of what?

Starch

In what polysaccharide form do plants store glucose to be available later as an energy source?

Starch

In what polysaccharide form do plants store sugar to be available later for energy?

Starch

The complex carbohydrate that you are most likely to have eaten recently is _____.

Starch

The polysaccharide that you are most likely to have eaten recently is ___.

Starch

What structural difference accounts for the functional differences between starch and cellulose?

Starch and cellulose differ in the glycosidic linkages between their glucose monomers.

The ovalbumin in egg white can be classified as which type of protein?

Storage

Another function of carbohydrates (as a class)

Structural Support

What types of proteins are usually fibrous and often water insoluble?

Structural proteins

Carbohydrates can function in which of the following ways?

Structural support and energy storage

The most common disaccharide

Sucrose

At what level of protein do BETA sheets of Amino Acids and Alpha-Helices, located at a distance from each other along the length of a polypeptide chain, come together to form a Globular Protein

Tertiary Structure

Which structure would be affected when a protein is denatured?

Tertiary structure

The overall three-dimensional shape of a single polypeptide is called the ___.

Tertiary structure The tertiary structure is determined by hydrogen bonds, hydrophobic R groups, ionic bonds between R groups, can der Waals interactions, and disulfide bridges.

B

Tertiary structure is NOT directly dependent on _____. A. bonds between sulfur atoms B. peptide bonds C. hydrogen bonds D. hydrophobic interactions E. ionic bonds

Tertiary Structure

Tertiary structure is achieved when a Protein folds in a compact, three dimensial shape stabilized by interactions between SIDE-CHAIN R Groups of Amino Acid

BLANK structure is determined by interactions between R groups, rather than interactions between BLANK constituents.

Tertiary, backbone

Where does the Calvin Cycle take place?

The Calvin cycle is a complex series of chemical reactions carried out in the stroma.

What factors allow some molecules to pass through a membrane more rapidly than others?

The Polarity of Membrane Phospholipids

phi

The _______ bond is between the nitrogen and alpha carbon.

tertiary

The _______ structure of a protein is the way that the entire polypeptide folds to form a unit of protein, a monomer. Tertiary structures can be globular, fibrous or barrel proteins of one or more secondary structure types

secondary

The _______ structure: or the way that this strand of amino acids orients itself in the protein structure: these are the alpha helix and beta strand structure that you may have heard about in earlier classes

hydrophobic interactions

The alpha-helices and beta-sheets are folded into a compact globule.

activation energy

The amount of energy required to initiate a chemical reaction; specifically, the energy required to reach the transition state.

thymine

The base that pairs Adenine in DNA

Cholesterol

The best-known sterol is cholesterol. It is needed in the body, but because the liver manufactures it, it is not essential in the diet. More than 90% of the cholesterol in the body is found in cell membranes. It is also part of myelin, the insulating coating on many nerve cells. Cholesterol is needed to synthesize other sterols, including vitamin D; bile acids, which are emulsifiers in bile; cortisol, which is a hormone that regulates our physiological response to stress; and testosterone and estrogen, which are hormones necessary for reproduction. In the diet, cholesterol is found only in foods from animal sources. Plant foods do not contain cholesterol unless it has been added in the course of cooking or processing. Plants do contain other sterols, however, and these plant sterols have a role similar to that of cholesterol in animals: They help form plant cell membranes. Plant sterols are found in small quantities in most plant foods; when consumed in the diet, they can help reduce cholesterol levels in the body.

Pinocytosis (cell-drinking)

The cell is engulfing extracellular fluid

Photosynthesis

The conversion of light energy to chemical energy that is stored in glucose or other organic compounds; occurs in plants, algae, and certain prokaryotes.

peptide bond

The covalent bond (C-N) bond formed by a condensation reaction between two amino acids; links the residues in peptides and proteins.

The peptide bond is _____.

The covalent bond joining two amino acids.

collagen

The fibrous protein constituent of bone, cartilage, tendon, and other connective tissue.

primary structure

The first level of protein structure; the specific sequence of amino acids making up a polypeptide chain.

Light Reactions

The first of two major stages in photosynthesis (preceding the Calvin cycle). These reactions, which occur on the thylakoid membranes of the chloroplast or on membranes of certain prokaryotes, convert solar energy to the chemical energy of ATP and NADPH, releasing oxygen in the process.

Which of the following describes a difference between DNA and RNA? (eText Concept 5.5) * RNA molecules consist of a single polynucleotide chain, whereas DNA molecules consist of two polynucleotide chains organized into a double helix. * One of their nitrogenous bases is different. * They contain different sugars. * The first and second listed responses are correct differences. * The first three listed responses all describe differences.

The first three listed responses all describe differences.

Stroma

The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water.

Quaternary structure

The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.

Carbon Fixation

The initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism (a plant, another photosynthetic organism, or a chemoautotrophic prokaryote).

Where is glycogen stored?

The liver and muscle of animals.

VLDLs, LDLs, HDLs

The liver can synthesize lipids. Lipids are transported from the liver in very-lowdensity lipoproteins VLDLs. Like chylomicrons, VLDLs are lipoproteins that circulate in the blood, delivering triglycerides to body cells. When the triglycerides have been removed from the VLDLs, a denser, smaller particle remains. About two-thirds of these particles are returned to the liver, and the rest are transformed in the blood into low-density lipoproteins LDLs. LDLs are primary cholesterol delivery system for cells. They contain a higher proportion of cholesterol than do chylomicrons or VLDLs. High levels of LDLs in the blood have been associated with an increased risk for heart disease. For this reason, they are sometimes referred to as "bad cholesterol." Because most body cells have no system for breaking down cholesterol, it must be returned to the liver to be eliminated from the body. This reverse cholesterol transport is accomplished by high-density lipoproteins (HDLs). HDL cholesterol is often called "good cholesterol" because high levels of HDL in the blood are associated with a reduction in the risk of heart disease.

Why are hydrocarbons insoluble in water?

The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.

Which feature of large biological molecules explains their great diversity?

The many ways that monomers of each class of biological molecule can be combined into polymers

Amylase is an enzyme that breaks down starch. Why can't the same enzyme break down cellulose?

The monosaccharide monomers in cellulose are bonded together differently than in starch The glucose monomers in cellulose are bonded in a beta glycosidic linkage, whereas those in starch have an alpha glycosidic linkage. The enzyme amylase is specific for the alpha glycosidic linkage.

Amylase is an enzyme that breaks down starch. Why can't the same enzyme break down cellulose? (Concept 5.2)

The monosaccharide monomers in cellulose are bonded together differently than in starch.

Amylase is an enzyme that breaks down starch. Why can't the same enzyme break down cellulose? (eText Concept 5.2) * The enzyme cannot attack cellulose because of its helical shape. * The monosaccharide monomers in cellulose are bonded together differently than in starch. * Cellulose molecules are much too large. * The bonds between the monosaccharide monomers in cellulose are much stronger. * Starch is made of glucose; cellulose is made of fructose.

The monosaccharide monomers in cellulose are bonded together differently than in starch. Correct. The glucose monomers in cellulose are bonded in a beta glycosidic linkage, whereas those in starch have an alpha glycosidic linkage. The enzyme amylase is specific for the alpha glycosidic linkage.

•Neutral (neither acidic nor basic) amino acids can be further classified as nonpolar or polar.

The neutral nonpolar amino acids have R groups that contain no charged atoms; most of these amino acids are not water soluble. The neutral polar amino acids have R groups that have a dipole moment. The partial charges in their R groups make these molecules generally water soluble.

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.

Cis and Trans Fatty Acids

The orientation of hydrogen atoms around the Carbon double bond distinguishes "cis" fatty acids from "trans" fatty acids. Most unsaturated fatty acids found in nature have double bonds in the cis configuration.

Quaternary structure

The overall protein structure that results from the aggregation of these polypeptide subunits.

quaternary structure

The overall three-dimensional shape of a protein containing two or more polypeptide chains (subunits); determined by the number, relative positions, and interactions of the subunits. Compare with primary, secondary, and tertiary structure.

tertiary structure

The overall three-dimensional shape of a single polypeptide chain, resulting from multiple interactions among the amino acid side chains and the peptide backbone. Compare with primary, secondary, and quaternary structure.

thymine, deoxyribose

The parts of a nucleic acid that occur exclusively in DNA include what?

uracil, ribose

The parts of a nucleic acid that occur exclusively in RNA include what?

adenine, guanine, cytosine, phosphate

The parts of a nucleic acid that occur in both DNA and RNA include what?

Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?

The phosphodiester linkages of the polynucleotide backbone would be broken.

active site

The portion of an enzyme molecule where substrates (reactant molecules) bind and react.

more stable, hydrolysis

The presence of deoxyribose as the sugar in DNA makes the molecule ______ _________ and less susceptible to ___________.

beta

The primary sequence of proteins can form two major secondary structures: the _______ strand, which often forms into a super-secondary structure of sheets, thus called _______ sheets, and the alpha helix.

amino

The primary structure is numbered from the _______ end of the polypeptide to the carboxyl end

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.

How does dehydration synthesis work in proteins?

The process is similar to that of carbohydrates, but the things being bonded are amino acids, not simple sugars.

Photophosphorylation

The process of generating ATP from ADP and phosphate by means of chemiosmosis, using a proton-motive force generated across the thylakoid membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis.

Transport Protein

The protein is allowing solute molecules to enter the cell

secondary structure

The result of hydrogen bonds between the repeating constituents of the polypeptide backbone

Structural isomers have __________.

The same formula, but different covalent arrangements

Calvin cycle

The second of two major stages in photosynthesis (following the light reactions), involving fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate.

transition state facilitation

The second stage (after initiation) in enzyme-catalyzed reactions, in which the enzyme enables formation of the transition state.

D

The secondary structure of a protein results from _____. A. ionic bonds B. hydrophobic interactions C. bonds between sulfur atoms D. hydrogen bonds E. peptide bonds

primary structure

The sequence of amino acids in a peptide or protein; also the sequence of nucleotides in a nucleic acid. Compare with secondary, tertiary, and quaternary structure.

Primary Structure

The sequence of amino acids in a protein or polypeptide is known as the primary structure. The primary structure will determine how the polypeptide will fold. There are twenty different amino acids and they can be combined in different ways to produce many different proteins

What is the primary structure of proteins

The sequence of amino acids.

Tertiary structure

The three-dimensional structure of a protein. A polypeptide is a molecule made from a large number of amino acids joined by condensation. This polypeptide is folded to form a protein. Some sections of the polypeptide coil and fold to produce the secondary structure of the protein. The whole protein then folds into a specific three-dimensional shape known as the tertiary structure. The tertiary structure of a protein is very important in determining its function.

E

The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases. A. ionic bonds B. covalent bonds C. hydrophilic interactions D. S—S bonds E. hydrogen bonds

•Acidic amino acids have acidic R groups

Their electrically charged R groups make these molecules highly soluble in water.

•Basic amino acids have basic R groups.

Their electrically charged R groups make these molecules highly soluble in water.

Which of the following do nucleic acids and proteins have in common?

They are large polymers.

What do all Amino Acid have in common?

They have a Carboxyl Group and an Amino Group attached to a central Carbon

A

This figure is an example of a(n) ___________. A. saturated fat B. unsaturated fat C. nucleic acid D. protein E. steroid

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

This protein illustrates all four levels of protein structure. primary: the order of amino acids in the polypeptide chain secondary: localized regions of alpha helices and beta pleated sheets tertiary: the overall three-dimensional shape of a polypeptide, stabilized by interactions between R groups quaternary: the association of more than one polypeptide subunit into a functional protein.

Describe Carbon Fixation in the Calvin Cycle

Three molecules of carbon dioxide are added to three molecules of a five-carbon sugar abbreviated RuBP. These molecules are then rearranged to form six molecules called 3-PGA, which have three carbons each.

What is the purpose of dehydration synthesis?

To bond two molecules together while removing water.

A membrane Transport what Ions?

Transport both Sodium (Na+) and Potassium (K+) Ions are transported against their concentration Gradients Both Ions are transported from where their concentration is low to where their concentration is high

T/F: -NH2 is an amino group.

True

T/F: Aldehydes, but not ketones, have H bound to C=O.

True

T/F: Hydrophobic R groups are nonpolar.

True

T/F: Saturated triglycerides have more hydrogens than unsaturated triglycerides.

True

The water-soluable portion of a phospholipid is the polar head, which generally consists of glycerol molecule linked to a phosphate group

True

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

True

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

True

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

True

True or False: All the information necessary for folding a peptide chain into its native structure is contained in the primary amino acid sequence. How was this shown

True. Anfinsen and White showed this by denaturing proteins with ß-mecaptoethanol and urea and then allowed proteins to reform. At first only 10% of proteins we functional, but after trail and error they were able to get as high as 80% of functional proteins. This experiment also gave evidence of protein chaperones.

True or False: Alpha helices have substantial net dipole moments? How does this dipole move?

True. This is because oxygen is partially negative and nitrogen is partially positive. The dipole moment moves down the alpha helix.

Which of RNA bases are Pyrimidines?

Uracil

__________ is always involved in hydrolysis reactions.

Water

What CANNOT pass directly through the phospholipds of the plasme membrance?

Water, Glucose and Hydrogen Ion Ions such as hydrogen ions and hydrophilic molecules such as water and glucose cannot rapidly pass directly through the phospholipids of a plasma membrane. To move through rapidly they musst pass through a membrane Transport Proteins

van der waals

Weak interactions that occur when atoms and molecules are very close together; based on the fact that because electrons are in constant motion, they may accumulate by chance in one part of the molecule or another, thus creating a charge for that instant

Amino Acid

What all Amino Acid have in common is an Amino Acid Group and a Carboxyl Group attached to a Central Carbon

phospholipid

What kind of structure is this?

E

What type of bond joins the monomers in a protein's primary structure? A. hydrophobic B. hydrogen C. S - S D. ionic E. peptide

Secondary Structure

Where the polypeptide chain forms either an alpha helix or a beta sheet

B

Which of these is NOT a lipid? A. phospholipid B. RNA C. cholesterol D. wax E. steroids

D

Which of these is a polysaccharide? A. lactose B. glucose C. sucrose D. cellulose E. galactose

D

Which of these is a source of lactose? A. sugar cane B. potatoes C. starch D. milk E. sugar beets

B

Which of these is rich in unsaturated fats? A. lard B. olive oil C. butter D. beef fat E. a fat that is solid at room temperature

bonds

Why does a primary sequence form a beta strand or an alpha helix? The folding of proteins into these two secondary structures depends on the freedom of movement of the _______ within the peptide chain.

Are phospholipids amphiphillic molecules?

Yes

Does the size of a specific protein change between species

Yes

Is the function of a protein dependent on the shape of that protein?

Yes

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. Water rejects nonpolar molecules such as fats, so fats travel inside particles that are coated with polar parts of phospholipids and proteins.

Can proteins change their shape to bind to a specific ligand?

Yes: lock-and-key fit

RNA

_____ is a nucleic acid.

C

_____ is the most abundant organic compound on Earth. A. Glycogen B. Lactose C. Cellulose D. Starch E. Glucose

Secondary

____________ structure describes the alpha-helices and beta-pleated sheets that are formed by hydrogen bonding between backbone atoms located near each other in the polypeptide chain.

Tertiary

____________ structure is achieved when a protein folds into a compact, 3D shape stabilized by interactions between side-chain R groups of amino acids.

Quaternary

____________ structure is the result of two or more protein subunits assembling to form a larger, biologically active protein complex.

Primary

____________ structure is the sequence of amino acids in a protein

Phospholipids

______________ are composed of a phosphate group, a glycerol, and fatty acids.

Tertiary structure

_________is considered to be largely determined by the biomolecule's primary structure, or the sequence of amino acids or nucleotides

Starch has what type of linkage of glucose?

a 1-4

Sugars are molecules that have __________ C:H:O and are called __________.

a 1:2:1 ratio of; carbohydrates

thymine

a base found in DNA (but not in RNA) and derived from pyrimidine

cytosine

a base found in DNA and RNA and derived from pyrimidine

cytosine

a base found in DNA and RNA and derived from pyrimidine; pairs with guanine

If a small droplet of triacylglycerol molecules is suspended in water, the fat molecules form a "ball of spaghetti" with no particular orientation. But if a droplet of phospholipid molecules is put in water, all the molecules point outward, toward the water. Phospholipids are forced into this orientation because phospholipids have _____. ( Concept 5.3)

a charged end and a noncharged end

If a small droplet of triacylglycerol molecules is suspended in water, the fat molecules form a "ball of spaghetti" with no particular orientation. But if a droplet of phospholipid molecules is put in water, all the molecules point outward, toward the water. Phospholipids are forced into this orientation because phospholipids have _____. (eText Concept 5.3) * two charged ends * three fatty acid molecules, all pointing in different directions * a charged end and a noncharged end * both a saturated fatty acid and an unsaturated fatty acid * two fatty acid molecules pointing in different directions

a charged end and a noncharged end Correct. The hydrocarbon tails of phospholipids are hydrophobic and are excluded from water. The negatively charged phosphate group and its attachments form a hydrophilic head that is attracted to water.

Dehydration synthesis

a chemical reaction in which two molecules become covalently bonded to each other with the removal of water

The peptide bond is _____. ( Concept 5.4)

a covalent bond joining amino acids together to form a polypeptide

The peptide bond is _____. (eText Concept 5.4) * a covalent bond joining amino acids together to form a polypeptide * a hydrogen bond joining amino acids together to form a polypeptide * a covalent bond joining simple sugars together to form a polypeptide * a covalent bond joining nucleotides together to form a nucleic acid * a hydrogen bond joining nucleotides together to form a nucleic acid

a covalent bond joining amino acids together to form a polypeptide

The peptide bond is __________.

a covalent bond joining amino acids together to form a polypeptide

The peptide bond is ___.

a covalent bond joining amino acids together to form a polypeptide.

alpha helix

a delicate coil held together by hydrogen bonding between every fourth amino acid

Saturated Fatty Acid

a fatty acid in which the carbon atoms are bonded to as many hydrogen atoms as possible; it therefore contains no carbon-carbon double bonds.

Unsaturated Fatty Acid

a fatty acid that contains one or more carbon-carbon double bond; could be either monosaturated containing one double bond or poly saturated containing two or more double bonds.

Lipids

a group of organic molecules, most of which do not dissolve in water. They include fatty acids, triglycerides, phospholipids and sterols.

Chylomicrons

a lipoprotein consisting of triglycerides, along with cholesterol and fat-soluble vitamins, packaged with phospholipids and cholesterol which are formed after long-chain fatty acids (from the digestion of triglycerides) have been absorbed into the mucosal cells and are reassembled into triglycerides.

polypeptide bond

a long chain of amino acids

The extracellular matrix of the animal cell has all of the following molecular components except __________.

a middle lamella

uracil

a nitrogen-containing base found in RNA (but not in DNA) and derived from pyrimidine

pyrimidine

a nitrogenous base that has a single-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; thymine, cytosine, or uracil

The components of nucleic acids are __________.

a nitrogenous base, a pentose sugar, and a phosphate

The components of nucleic acids are __________.

a nitrogenous base, a pentose sugar, and a phosphate (NPP) (cold sugar tastes like phosphorus)

A nucleotide consists of three parts

a nitrogenous base, a pentose sugar, and one or more phosphate groups. ATP consists of a nitrogenous base (adenine), a pentose sugar, and three phosphate groups.

A nucleotide is made of which of the following chemical components?

a nitrogenous base, a phosphate group, and a pentose sugar

A nucleotide is made of which of the following chemical components? ( Concept 5.5)

a nitrogenous base, a phosphate group, and a pentose sugar

A glucose molecule is to starch as _____. ( Concept 5.5)

a nucleotide is to a nucleic acid

A glucose molecule is to starch as _____. (eText Concept 5.5) * a nucleic acid is to a polypeptide * a protein is to an amino acid * a nucleotide is to a nucleic acid * a steroid is to a lipid * an amino acid is to a nucleic acid

a nucleotide is to a nucleic acid

A glucose molecule is to starch as ___.

a nucleotide is to a nucleic acid Nucleotides are the monomers that make nucleic acid polymers, just as glucose is the monosaccharide from which starch is constructed

A glucose molecule is to starch as _____.

a nucleotide is to a nucleic acid (Nucleotides are the monomers that make nucleic acids, just as glucose is the monosaccharide from which starch is constructed.)

motif

a nucleotide or amino-acid sequence pattern that is widespread and has, or is conjectured to have, a biological significance

ribose

a pentose sugar important as a component of ribonucleic acid

In a hydrolysis reaction, _____. In this process, water is _____.

a polymer breaks up to form monomers ... consumed

In a hydrolysis reaction, _____, and in this process water is _____. ( Concept 5.1)

a polymer is broken up into its constituent monomers ... consumed

The organic molecule called DNA is an example of ....

a polymer made of nucleotides.

Cellulose

a polysaccride that is a major component of the tough walls that enclose plant cells, not digestable

hydrogenation

a process by which hydrogen atoms are added to the carbon-carbon double bonds of unsaturated fatty acids for the purpose of "synthesizing" a saturated fatty acid. A disadvantage of such a process is that it may convert the fatty acid from a "cys" to "trans" configuration.

What is the most structurally sophisticated molecule we know of?

a protein

Sickle-cell anemia is a disease that is caused by __________ in the __________ of the protein.

a single amino acid change; primary structure

What are monomers?

a single molecule of a polymer

What does amphiphiliic mean?

a term describing a chemical compound possessing both hydrophillic (water-loving, polar) and hydrophobic (water -hating) properties.

Lipoproteins

a water-soluble envelope of protein, phospholipids, and cholesterol form particles called lipoproteins, since long-chain fatty acids, cholesterol, and fat soluble vitamins are not soluble in water and are not absorbed directly into the blood and must be packaged for transport.Different types of lipoproteins transport dietary lipids from the small intestine to body cells, from the liver to body cells, and from body cells back to the liver for disposal.

What do a-helices and b-pleated sheets look like?

a-helices are coiled b-pleated sheets are folded

alpha beta glucose are in equilibrium in aqueous solutions at a ration of __________

a:B 36:64

In Miller's 1953 laboratory experiment, __________.

abiotic compounds cycled through the apparatus and were sampled for organic compounds

Chloroplasts

absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water.

Choose the pair of terms that completes this sentence about functional groups in organic chemistry: Carboxyl is to _____ as _____ is to base.

acid ... amino

Choose the pair of terms that completes this sentence about functional groups in organic chemistry: Carboxyl is to __________ as __________ is to base.

acid; amino

Charged Amino Acids

acidic: aspartic, glutamine basic: lysine, argnine, histidine

What does a trans isomer look like?

across

Manufacturers make vegetable oils solid or semisolid at room temperature by ___.

adding hydrogen atoms to the double bonds in the fatty acid hydrocarbon chains

Manufacturers make vegetable oils solid or semisolid at room temperature by _____. ( Concept 5.3)

adding hydrogen atoms to the double bonds in the fatty acid hydrocarbon chains

Manufacturers make vegetable oils solid or semisolid at room temperature by _____. (eText Concept 5.3) * adding hydrogen atoms to the single bonds of the fatty acid hydrocarbon chains * adding hydrogen atoms to the double bonds in the fatty acid hydrocarbon chains * removing hydrogen atoms and forming additional double bonds in the fatty acid hydrocarbon chains * removing hydrogen atoms and forming additional single bonds in the fatty acid hydrocarbon chains * None of the listed responses is correct.

adding hydrogen atoms to the double bonds in the fatty acid hydrocarbon chains No. If hydrogen atoms were removed, additional double bonds would be formed.

Manufacturers make vegetable oils solid or semisolid by _____.

adding hydrogens

Hydrolysis BLANK a water molecule, breaking a bond.

adds

Hydrolysis

adds a water molecule, breaking a bond

hydrolysis

adds water to break a molecule apart

Examples of purines

adenine (A) and guanine (G)

On the basis of the principle of complementary base pairing, you would expect the percentage of _____ to be equal to the percentage of _____. ( Concept 5.5)

adenine ... thymine

On the basis of the principle of complementary base pairing, you would expect the percentage of _____ to be equal to the percentage of _____. (eText Concept 5.5) * adenine ... thymine * thymine ... guanine * thymine ... cytosine * adenine ... guanine

adenine ... thymine

Nitrogenous bases are classified as either purines or pyrimidines. Examples of purines are __________.

adenine and guanine

What nitrogenous bases are purines?

adenine and guanine

Which of RNA bases are purines?

adenine and guanine

purines

adenine and guanine are what

Nitrogenous bases are classified as either purines or pyrimidines. Examples of purines are __________.

adenine and guanine; There are two families of nitrogenous bases: pyrimidines and purines. A pyrimidine has one six-membered ring of carbon and nitrogen atoms. The members of the pyrimidine family are cytosine (C), thymine (T), and uracil (U). Purines are larger, with a six-membered ring fused to a five-membered ring. The purines are adenine (A) and guanine (G). The specific pyrimidines and purines differ in the chemical groups attached to the rings. Adenine, guanine, and cytosine are found in both DNA and RNA; thymine is found only in DNA and uracil only in RNA.

On the basis of the principle of complementary base pairing, you would expect the percentage of ___ to be equal to the percentage of __.

adenine...thymine

What does a cis isomer look like?

adjacent

Although the structures of the functional groups important to life vary in chemical structure, they share one thing in common: They _____.

all are hydrophilic and increase the organic compound's water solubility

Although the structures of the functional groups that are most important to life vary, they share one thing in common: They __________.

all are hydrophilic and increase the organic compound's water solubility

parallel beta-sheet :

all bonded strands have the same N to C direction, separated by long sequence distances

parallel beta sheet

all of the N-termini of successive strands are oriented in the same direction

What do unsaturated fats have?

always a cis double bond between carbon and carbon stay liquid

A functional group on a molecule in solution carries two H atoms at pH 9 and three H atoms at pH 3. The functional group is probably. . .

amino

Which chemical group is most likely to be responsible for an organic molecule behaving as a base?

amino

Bioinformatics uses computer programs to predict protein structure from BLANK sequences.

amino acid

Proteins

amino acid putting a protein together

Protein molecules are polymers (chains) of _____. ( Concept 5.4)

amino acid molecules

Protein molecules are polymers of _____.

amino acid molecules

Protein molecules are polymers (chains) of ___.

amino acid molecules Polymers of amino acids are called polypeptides. A protein consists of one or more polypeptides folded into specific conformations

Protein molecules are polymers (chains) of _____. (eText Concept 5.4) * sucrose molecules * DNA molecules * amino acid molecules * purines and pyrimidines * fatty acid molecules

amino acid molecules Correct. Polymers of amino acids are called polypeptides. A protein consists of one or more polypeptides folded into specific conformations.

Proteins

amino acid monomer strung together to make polypeptides

Primary Structure

amino acid sequence (covalent, peptide bonds)

Proteins are polymers of

amino acids

Proteins are polymers of _____.

amino acids

What are the monomers of proteins?

amino acids

Which class(es) of amino acids possess side chains that would be unable to form hydrogen bonds with water?

amino acids with nonpolar side chains

hydrophobic interactions

amino acids with nonpolar side chains end up in clusters at the core of the protein, out of contact with water; caused by the action of water molecules, which exclude nonpolar substances as they form hydrogen bonds with each other and with hydrophilic parts of the protein

Peptide bonds are formed between _____. However, it is the properties of the _____ that determine the overall shape of the protein.

amino and carboxyl groups ... R group

Proteins are made up of

amino group + R goup + carboxyl group

What type of molecule can interact with oils and water molecules

amphilic molecules

Phospholipids are ___________ molecules

amphillic

Ester

an alcohol and acid linked together

amino acid residues

an amino acid in a polypeptide that is not the N or C terminal AA

Linoleic Acid (Omega-6)

an essential polyunsaturated fatty acid which is characterized by its location of the first double carbon bond between the sixth and seventh Carbons on the omega side of the chain. such as arachidonic acid. They help stimulate skin and hair growth, maintain bone health, regulate metabolism, and maintain the reproductive system. Omega-6 fatty acids play a crucial role in brain function, as well as normal growth and development.

Alpha-Linoleic Acid (Omega-3)

an essential polyunsaturated fatty acid which is characterized by the location of the first double carbon bond between the third and fourth carbon on the omega side of the chai; CH3. Such as Eicosapentanoic acid;EPA and docosahectanoic acid;DHA found in fatty fish. Research shows that omega-3 fatty acids reduce inflammation and may help lower risk of chronic diseases such as heart disease, cancer, and arthritis. Omega-3 fatty acids are highly concentrated in the brain and appear to be important for cognitive (brain memory and performance) and behavioral function.

Triglycerides

animal fats, plant oils, glycerol head, 3 fatty acid tails

Glycogen

animal polysaccharide highly branched fuel source for humans in liver and muscles

Glycogen

animal starch, branched amylose chains

Chains of beta pleated sheets

antiparallel (most stable) and parallel

What are lipids?

are fats, phospholipids and steroids that mix poorly with water

Lipids differ from other large biological molecules in that they ___.

are not true polymers Lipids are not all made up of the same type of monomer. Their association as a group (fats, phospholipids, and steroids) is related to their solubility behavior.

Lipids differ from other large biological molecules in that they _____. ( Concept 5.3)

are not truly polymers

Lipids differ from other large biological molecules in that they _____. (eText Concept 5.3) * do not contain nitrogen and phosphorus atoms * do not have specific shapes * are much larger * are not truly polymers * do not contain carbo

are not truly polymers

Lipids differ from other large biological molecules in that they _____.

are not truly polymers (Lipids are not all made of identical monomers bonded together. Their association as a group is related to their behavior rather than their structure.)

antiparallel beta sheet

arrangement, the successive β strands alternate directions so that the N-terminus of one strand is adjacent to the C-terminus of the next

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

as a component of animal cell membranes

Carbohydrates are mainly used in our bodies _____.

as fuel

Secondary Structure

begins to fold and hydrogen bonds form

Dehydration removes a water molecule, forming a new BLANK.

bond

What is a phophoanhydride bond?

bond between the phosphates in the ATP

nucleotide

building block of a nucleic acid (DNA and RNA)

How are amino acids bonded together?

by a peptide bond

A simple sugar is composed of equal carbon and water, which gave rise to the general name of any sugar as a ______.

carbohydrate

Compounds that have _____ in it are said to be organic.

carbon

nitrogenous base

carbon ring structure found in DNA or RNA that contains one or more atoms of nitrogen; includes adenine, guanine, cytosine, thymine and uracil

Carbohydrates contain

carbon, hydrogen, and oxygen

Depending on the location of the BLANK group, the sugar is an aldose or a ketose.

carbonyl

Sugars have a(n) __________ group that interacts with a _________ group that forms ring structures when the dry molecule is placed in water.

carbonyl (-C=O); hydroxyl (-OH)

Monosaccharides are classified by the location of the BLANK group (as aldose or ketose) and The number of carbons in the BLANK skeleton.

carbonyl, carbon

Which of the following components of a tossed salad will pass through the human digestive tract and be digested the least? ( Concept 5.2)

cellulose (in the lettuce)

Which of the following components of a tossed salad will pass through the human digestive tract and be digested the least? (eText Concept 5.2) * cellulose (in the lettuce) * starch (in the croutons) * protein (in the bacon bits) * sugar (in the dressing) * oil (in the dressing)

cellulose (in the lettuce) Correct. Cellulose contains glycosidic linkages that cannot be broken by human digestive enzymes.

Which of the following is a polymer? ( Concept 5.2)

cellulose, a plant cell wall component

Which of the following is a polymer? (eText Concept 5.2) cellulose, a plant cell wall component fructose, a component of sucrose glucose, an energy-rich molecule triacylglycerol, or fat testosterone, a steroid hormone

cellulose, a plant cell wall component Correct. The polysaccharide cellulose is a major component of plant cell walls. It is a polymer composed of many glucose monomers joined together by glycosidic linkages.

The organelle that is a plant cell's compartment for the storage of inorganic ions such as potassium and chloride is the __________.

central vacuole

Animal cells have unique organelles called __________ that are composed of structures called __________.

centrosomes; centrioles

Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form? ( Concept 5.4)

chaperonins

Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form? (eText Concept 5.4) * fibrous proteins * enzymes * receptor proteins * antibodies * chaperonins

chaperonins Correct. Chaperonins shield proteins from "bad influences" (interactions with other molecules in the cytoplasm) while they are folding into their functional forms.

Enzymes are a type of protein that acts as a catalyst to speed up BLANK reactions.

chemical

At a conference, the speaker's grand finale was sautéing mealworms (insect larvae) in butter and serving them to the audience. They were crunchy (like popcorn hulls) because their exoskeletons contain the polysaccharide _____. ( Concept 5.2)

chitin

At a conference, the speaker's grand finale was sautéing mealworms (insect larvae) in butter and serving them to the audience. They were crunchy (like popcorn hulls) because their exoskeletons contain the polysaccharide _____. (eText Concept 5.2) * chitin * glycogen * cellulose * collagen * linoleic acid

chitin Correct. Chitin is the structural polysaccharide found in arthropod exoskeletons.

What is the most important and common steroid?

cholesteral

The molecule with four fused rings that is found in animal membranes and is the precursor of vertebrate sex hormones is __________.

cholesterol

What builds sex hormones?

cholesterol

what is in bile?

cholesterol, Deoxycholic acid, taurocholic acid, phospholipid

What's a trans fat?

cis double bond Straight: rare most are artificially made take an unsaturated liquid oil can force in hydrogens to convert some double bonds to a single bond(produce unsaturated fats)

When comparing saturated and naturally occurring unsaturated fats, the unsaturated fats have __________ and are __________ at room temperature.

cis double bonds; liquids

When a double bond joins two carbon atoms, __________ can form.

cis-trans isomers

BLANK is a fibrous protein consisting of three polypeptides coiled like a BLANK

collagen, rope

alpha helix

common motif in the secondary structure of proteins

An enzyme inhibitor that is roughly the same shape as the substrate and binds at the active site is termed a(n) _____ inhibitor

competitive

nucleotide

composed of a nucleobase (nitrogenous base), a five-carbon sugar (either ribose or 2'-deoxyribose), and one to three phosphate groups

During protein synthesis, the covalent bond between amino acids is formed by the process of _____.

condensation

Loops and Turns

connect alpha helices and B strands and allow a peptide chain to fold back on itself to make compact structure

beta sheet

connected laterally by at least two or three backbone hydrogen bonds

beta sheet

consist of beta strands connected laterally by at least two or three backbone hydrogen bonds

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

The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) _____ bond. ( Concept 5.1)

covalent

The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) _____ bond. (eText Concept 5.1) * hydrogen * ionic * van der Waals * peptide * covalent

covalent

The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) __________ bond.

covalent

How are monosaccharides joined?

covalent bonds

The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) __________ bond.

covalent; Monomers are joined together by a dehydration reaction in which two molecules are covalently bonded to each other through the loss of a water molecule.

Macromolecules are large molecules composed of thousands of BLANK connected atoms.

covalently

Scientists use X-ray BLANK to determine a protein's structure.

crystallography

proximal

cysteines can form disulfide bonds when they are _______ to each other.

What do trans fats do to HDL (good cholesterol)?

decrease

3D structure

defined by the primary structure

What is the process by which monomers are linked together to form polymers? ( Concept 5.1)

dehydration or condensation reactions

What is the process by which monomers are linked together to form polymers? (eText Concept 5.1) * coiling * protein formation * hydrolysis * monomerization * dehydration or condensation reactions

dehydration or condensation reactions

How are fatty acids joined to glycerol?

dehydration synthesis

What polymerizes molecules together?

dehydration synthesis

Cells invest energy to carry out BLANK reactions. The process is aided by BLANK.

dehydration, enzymes

A disaccharide is formed when a BLANK reaction joins two monosaccharides. This covalent bond is called a BLANK.

dehydration, glycosidic linkage

3D structure

determines function

Geometric isomers are molecules that _____.

differ in the arrangement of their atoms about a double bond

Lactose, the sugar in milk, is a _____, because it can be split into two monosaccharides.

disaccharide

cysteine

disulfide bonds; strongest nucleophile of amino acid residues; two could come together to form a cysteine bridge

Non-ionized carboxyl groups cause a molecule to act as an acid because they ...

donate H+ ions to water

unsaturated

double bond , or oils, liquid at room temp, come from plants and fish usually

In living organisms, DNA exists as a __________ with the strand(s) __________.

double helix; running antiparallel

purines

double ring

Alpha helix bonds

each C=O forms bond with amide hydrogen of residue n+4

What is carbon used for?

emulsifier gets thing to dissolve well its found in bile

When molecules are mirror images, they're ________.

enantiomers

Two main roles of carbohydrates

energy structure

Carbohydrates are used in our bodies mainly for _____. ( Concept 5.2)

energy storage and release

Carbohydrates are used in our bodies mainly for __________.

energy storage and release

Carbohydrates are used in our bodies mainly for _____. (eText Concept 5.2) * building genetic material * lipid storage * structural molecules, such as hair and fingernails * energy storage and release * membrane construction

energy storage and release Correct. Simple sugar molecules, stored in polysaccharides such as glycogen in animals and starch in plants, are a major energy source for cellular work

primary structure

equivalent to specifying the sequence of its monomeric subunits, e.g., the nucleotide or peptide sequence

Some lipids are formed when fatty acids are linked to glycerol. These subunits are linked together by _____. ( Concept 5.3)

ester linkages

Some lipids are formed when fatty acids are linked to glycerol. These subunits are linked together by _____. (eText Concept 5.3) * ester linkages * glycosidic linkages * peptide bonds * ionic bonds * phosphodiester linkages

ester linkages

Some lipids are formed when fatty acids are linked to glycerol. These subunits are linked together by ___.

ester linkages In making a fat, each of the three fatty acid molecules is bonded to a glycerol by an ester linkage type of covalent bond.

True or false, Monosaccharides usually exist in linear form?

false

True or false: The R groups are involved in the H bonds?

false

"polymer "fatty acids" (lipids are do not have monomers or polymers)

fats and lipids

Lipids are composed of what three molecules part?

fats,membrane lipids, steroids

the monomer of a lipid

fatty acid polymer chains

Phospholipids are composed of three molecule parts?

fatty acids, glycerol, polar group

Tertiary Structure

final folded shape that is determined by the primary structure

deoxyribose

five-carbon sugar that is a component of DNA nucleotides

Secondary Structure

formed by hydrogen bonding that occurs between carboxyl an amino acid groups of non-adjacent amino acids

alpha helix

forming a generally twisted, pleated sheet (the most common form of regular secondary structure in proteins is the

Phospholipids

found in membranes, glycerol head, 2 fatty acid tails, phosphate group

Hemoglobin is a globular protein consisting of BLANK polypeptides: two BLANK and two BLANK chains.

four, alpha, beta

Proteins include a diversity of structures, resulting in a wide range of BLANK

functions

Steroids are lipids characterized by a carbon skeleton consisting of four BLANK.

fused rings

The amino acid sequence of a polypeptide is programmed by a unit of inheritance called a BLANK.

gene

What do steroids do for our cells?

give structure

What does cholesterol do for cell membranes?

give structure

Starch is a storage polysaccharide composed entirely of BLANK monomers.

glucose

Which of the following carbohydrate molecules has the lowest molecular weight? ( Concept 5.2)

glucose

Which of the following carbohydrate molecules has the lowest molecular weight? (eText Concept 5.2) * glucose * cellulose * sucrose * chitin * lactose

glucose

Sucrose

glucose + fructose

Lactose

glucose + galactose

Maltose

glucose + glucose

E

glucose + glucose —> _____ by _____. A. lactose + water ... hydrolysis B. starch + water ... dehydration synthesis C. sucrose + water ... dehydration synthesis D. cellulose + water ... hydrolysis E. maltose + water ... dehydration synthesis

an example of monomers in a carbohydrate

glucose, DNA, and RNA

Name monosacchrides

glucose, frutose, glactose, ribose, dioxyribose

Nonpolar Side Groups

glycine alarine valine leucine isoleucine methionine phenylalanine tryptophan proline

A polysaccharide that is used for storing energy in human muscle and liver cells is _____. ( Concept 5.2)

glycogen

A polysaccharide that is used for storing energy in human muscle and liver cells is _____. (eText Concept 5.2) * chitin * glucose * starch * glycogen * cellulose

glycogen

A polysaccharide that is used for storing energy in human muscle and liver cells is __________.

glycogen

Animals store glucose in a polysaccharide called BLANK.

glycogen

How are monosaccharides are joined together?

glycosidc linkage by dehydration synthesis

What joins disaccharides together?

glycosidic bond

How are disaccharides joined?

glycosidic bonds

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

glycosidic linkage

The subunits (monomers) in cellulose are linked together by _____. ( Concept 5.2)

glycosidic linkages

The subunits (monomers) in cellulose are linked together by __________.

glycosidic linkages

the subunits (monomers) in cellulose are linked together by _____. (eText Concept 5.2) * glycosidic linkages * peptide bonds * ionic bonds * phosphodiester linkages * ester linkages

glycosidic linkages

The subunits in cellulose are linked together by ___.

glycosidic linkages The glucose monomers of cellulose are linked together by a specific type of covalent bond known as a glycosidic linkage

unsaturated fats

have double bonds in the carbon chains of their fatty acids

Denaturation

heat or chemicals can disrupt protein structure

Chaperonins

help form large macromolecule complexes, refold improperly folded proteins

Chaperone proteins

help proteins fold correctly, heat shock proteins (able to maintain structure at high temps)

Nucleic acids store, transmit, and help express BLANK information.

hereditary

Steroids

hormone, venoms, pigments (chlorophyll)

Observing a fluorescent micrograph cell with intermediate filaments would help you identify the cell as a __________.

human skin cell

The secondary structure of proteins results because of _____ bonding between molecules in the protein molecules' backbone.

hydrogen

The final three-dimensional folding of protein molecules (tertiary structure) can result from which of the following types of chemical interactions?

hydrogen bonding hydrophobic interactions covalent bonding

Cellulose is strengthened by what type of bonds amoung parallel strands?

hydrogen bonds

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

hydrogen bonds

The secondary structure of a protein results from _____.

hydrogen bonds; Electronegative oxygen and nitrogen atoms leave hydrogen atoms with partial positive charges.

The secondary structure of a peptide backbone is stabilized by __________ forming either a(n) __________ or a(n) __________.

hydrogen bonds; α helix; β pleated sheet

What does an amino acid look like?

hydrogen, amino, carboxyl and r group

These interactions between R groups include BLANK bonds, BLANK bonds, BLANK interactions, and van der Waals interactions.

hydrogen, ionic, hydrophobic

In BLANK, bonds are broken by the addition of water molecules.

hydrolysis

The covalent bonds connecting monomers in a polymer are disassembled by BLANK, a reaction that is effectively the reverse of dehydration.

hydrolysis

Structure of a phospholipid

hydrophilic head- phosphate group(outward) hydrophobic tail- fatty acid tail (center)

Lipids are a diverse group of BLANK molecules.

hydrophobic

Which is the term for compounds that do not mix with water?

hydrophobic

Which is the term for compounds that do not mix with water? ( Concept 5.3)

hydrophobic

Which is the term for compounds that do not mix with water? (eText Concept 5.3) * proteins * hydrophilic * hydrogen-bonded * phospholipids * hydrophobic

hydrophobic Correct. Hydrophobic compounds are those that are insoluble in water.

The fatty acid tails of a phospholipid are _____ because they _____. ( Concept 5.3)

hydrophobic ... have no charges to which water molecules can adhere

The fatty acid tails of a phospholipid are _____ because they _____. (eText Concept 5.3) * hydrophobic ... have no charges to which water molecules can adhere * hydrophobic ... dissolve easily in water * hydrophobic ... consist of units assembled by dehydration reactions * hydrophilic ... consist of units assembled by dehydration reactions * hydrophilic ... are easily hydrolyzed into their monomers

hydrophobic ... have no charges to which water molecules can adhere

Tertiary structure of Globular Proteins

hydrophobic AA generally on the inside, hydrophilic AA generally on outside

R groups

hydrophobic/nonpolar, found on the inside of the folded chain, away from water

Defensive proteins are manufactured by the _____ system.

immune

Purpose of disaccharides

in animals: nutrition, in plants: transport

Emulsifiers

in foods, substances that allow fat and water to mix. For example, lecithin. It is used as an emulsifier in margarine and baked goods to prevent oil from separating from the other ingredients. In the body, lecithin is a major constituent of cell membranes. It is also used to synthesize the neurotransmitter acetylcholine, which activates muscles and plays an important role in memory.

right

in secondary structures: For the most part, alpha helices are going to be _______ handed, that is, as the helix extends from the N-terminus of the polypeptide to the C-terminus, the turn of the helix will be counterclockwise, or if you hold out your right hand with the thumb up, indicating the elongation axis of the helix, then your fingers curve in the direction of the helix.

A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized __________.

in the rough endoplasmic reticulum

The walls of plant cells are largely composed of polysaccharides and proteins that are synthesized __________.

in the rough endoplasmic reticulum and in the Golgi apparatus

alpha helix

in which every backbone N-H group donates a hydrogen bond to the backbone C=O group of the amino acid four residues earlier ( hydrogen bonding).

A denatured protein is biologically BLANK.

inactive

What do trans fats do to LDL (bad cholesterol)?

increase

Nucleic Acids

information molecule of proteins, lipids, and carbohydrates

Chitin

insect exoskeletons

Molecular structure and function are BLANK.

inseparable

Quaternary structure

is a larger assembly of several protein molecules or polypeptide chains, usually called subunits in this context

nucleotides

is a nucleic acid monomer consisting of a nitrogen base, a pentose sugar, and a phosphate group. Nucleotides joined together by covalent bonds called phosphodiester linkages form nucleic acid molecules.

alpha helix

is a right-handed coiled or spiral conformation, in which every backbone N-H group donates a hydrogen bond to the backbone C=O group of the amino acid four residues earlier ( hydrogen bonding).

a beta turn

is a short secondary structure, which enables the structure to have a 180° turn

hairpin

is a special case of a turn, in which the direction of the protein backbone reverses and the flanking secondary structure elements interact. For example, a β-hairpin connects two hydrogen-bonded, antiparallel β-strands

beta strand

is a stretch of polypeptide chain typically 3 to 10 amino acids long with backbone in an almost fully extended conformation

turn

is an element of secondary structure in proteins

α-turn

is characterized by (a) hydrogen bond(s) in which the donor and acceptor residues are separated by four residues (

pro

is common in beta turns

What is peptidoglycan?

is similar to chitin, but includes alternating N-acetyl-murmaic acids subunits that are covalenty crosslinked

beta sheet

is the β hairpin, in which two antiparallel strands are linked by a short loop of two to five residues, of which one is frequently a glycine or a proline

What is a nucleoside?

it consists of a nitrogenous base covalently attached to a sugar (ribose or deoxyribose) but without the phosphate group.

Whats a nucleotide?

it consists of a nitrogenous base, a sugar (ribose or deoxyribose) and one to three phosphate groups.

Why does starch use a repeating a1-4 linkage of glucose?

it is created exclusively by plants and used as form of energy storage

What happens when a phosphoanhydride bond is hydrolysised?

it releases energy

What determines the function of a protein?

its shape

Fibrous proteins

keratin and collagen and elastin

In fats what does the double bond to carbons cause the fat to do?

kink, and make it a liquid because they can't stack on top of each other

The carbon skeleton can vary in all of the following except __________.

lacking hydrogen atoms

Within cells, small organic molecules are joined together to form BLANK molecules.

larger

Enzymes can perform their functions repeatedly, functioning as workhorses that carry out the processes of BLANK

life

What are the two stages of photosynthesis

light dependent and light independent

primary structure

linear sequence of amino acid residues, covalent bonding including disulfide bonds -SS-

The sex hormones estrogen, progesterone, and testosterone belong to which class of molecules? (Concept 5.3)

lipids

The sex hormones estrogen, progesterone, and testosterone belong to which class of molecules? (eText Concept 5.3) * proteins * lipids * amino acids * nucleic acids * carbohydrates

lipids Correct. Steroids, such as estrogen, progesterone, and testosterone, are lipids based on their insolubility in water. The molecules are characterized by a carbon skeleton consisting of four fused rings of carbon atoms.

where is bile found?

liver

Polyssaccharides

long polymer of many sugars

Polysaccharide

long polymers made up of monosaccharides used for energy storage

protein

macromolecule consisting of one or more polypeptide chains composed of 50 or more amino acids linked together. Each protein has a unique sequence of amino acids and, in its native state, a characteristic three-dimensional shape.

Each cell has thousands of different kinds of BLANK.

macromolecules

beta sheet

made up of beta strands. in antiparallel, hydrogen bonding is straight across, parallel is two residues farther along the opposite chain.

secondary structure

main chain H-bonding (alpha helix, b sheet, b turn)

Why is it important that cysteine has a sulfhydryl group?

makes disulfide bridge

Polypeptide

many amino acids joined together by peptide bonds 1: or more polypeptides folded into specific conformation

In the pharmaceutical industry, two enantiomers of a drug ...

may not be equally effective.

The chemical group that is involved in regulating DNA is the

methyl group (-CH3)

The proper three-dimensional shape and folding of a protein is assisted by _________.

molecules called chaperonins

Fatty Acids

molecules made up of a chain of Carbons linked to Hydrogen, with an acid group at one end of the chain.

These small building-block molecules are called BLANK.

monomer

Monosaccharides

monomer of carbohydrates,

nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

Polymers are always made up of _______.

monomers

The repeated units are small molecules called BLANK.

monomers

polymers are made up of

monomers

The structure and function of a polysaccharide are determined by its sugar BLANK and the BLANK of glycosidic linkages.

monomers, positions

carbohydrates include

monosaccharide's, starch, polysaccharide, disaccharide

The simplest carbohydrates are BLANK, or single sugars.

monosaccharides

What is the monomer of carbohydrate?

monosaccharides

Monomers

monosaccharides (simple sugar)

A ____ cannot be hydrolyzed any further.

monsaccharide

RNA nucleotides contain __________ than DNA nucleotides.

more oxygen

How many different types of proteins are known?

more than 100,000

Goals of Protein

movement, muscle contraction provide support: structural source of amino acids for later use: storage move molecules around body: transparent coordinate body functions and responses based on circumstances receives and enables cell to respond to signal protect us from foreign invaders like bacteria and viruses

Microfilaments function in cell motility including __________.

muscle contraction, amoeboid movement, and cytoplasmic streaming in plants

Acids have what kind of charge

negative

nucleotides have?

nitrogenous base, 5-carbon sugar (ribose or deoxyribose) phosphate group

A nucleotide is made of which of the following chemical components? (eText Concept 5.5) * a series of nitrogenous bases, a nucleic acid backbone, and a hexose sugar * a nitrogenous base, an amino acid, and a pentose sugar * a nitrogenous base, an amino acid, and a phosphate group * a nitrogenous base, a fatty acid, and an amino acid * a nitrogenous base, a phosphate group, and a pentose sugar

nitrogenous base, a phosphate group, and a pentose sugar Correct. Each nucleotide consists of three parts: an organic molecule, called a nitrogenous base; a 5-carbon sugar, called a pentose; and a phosphate group that serves in the phosphodiester covalent bond that forms a bridge between adjacent nucleotides.

Are fats polymers?

no

Can humans break down B 1-4 bonds found in cellulose?

no only bacteria and other microorganisms can

Can we break down molecules in their polymerized form?

no, we can't break them down

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

none of them dissolves in water

Carbon and Hydrogen present means?

nonpolar

Lipids are hydrophobic because they consist mostly of hydrocarbons, which form BLANK covalent bonds.

nonpolar

is cholesterol nonpolar or polar

nonpolar-because it doesn't interact with water, classifying it as a lipid

The endoplasmic reticulum is part of the endomembrane system, which also includes the __________.

nuclear envelope, the Golgi apparatus, lysosomes, and vesicles

Another method is BLANK (NMR) spectroscopy, which does not require protein crystallization.

nuclear magnetic resonance

The region of a bacterial cell that contains the genetic material is called the __________.

nucleoid

Nucleic acids are polymers of what?

nucleotide

With the addition of what a phosphate the nucleoside becomes what?

nucleotide

Genes are made of DNA, a nucleic acid made of monomers called BLANK.

nucleotides

Enzyme molecules require a specific shape to perform their catalytic function. Which of the following might alter the shape of an enzymatic protein? ( Concept 5.4)

of the listed responses are correct: change in salt concentration or pH; mixing in a chemical that removes hydrogen bonds; heating the protein; denaturing the protein

Which of the following is the major energy storage compound of plant seeds?

oils

Which of the following is the major energy storage compound of plant seeds? ( Concept 5.3)

oils

Which of the following is the major energy storage compound of plant seeds? (eText Concept 5.3) * cellulose * glycogen * lipids * amylose * oils

oils

Which of these is rich in unsaturated fats?

olive oil

acids/bases are located where

on exterior of 3-demensional structure

uracil

one of the four bases that combine with sugar and phosphate to form a nucleotide subunit of RNA; uracil pairs with adenine

fibrous

one of the three protein structures: the _______ protein, where monomers can interact to form long thin proteins, such as we see with collagen and myosin.

Monosaccharides

one sugar fructose, glucose, galactose

glycine

only A-chiral amino acid residue, in places where you need a lot of flexiblity

Galactose an mannose are what type of isomers of glucose?

optical

Plants produce almost one hundred billion tons of cellulose per year. It is the most abundant BLANK compound on Earth.

organic

Inorganic carbon such as CO2 differs from organic carbon because __________.

organic carbon always has a hydrogen atom covalently attached to it

BLANK is the key to the chemistry of life.

organization

In mechanism, photophosphorylation is most similar to

oxidative phosphorylation in cellular respiration.

isoelectric point

pI- the pH at which the net charge is zero

Nucleic acid

parts of a nucleotide double helix

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

peptide

Tertiary structure is NOT directly dependent on

peptide bonds

Tertiary structure is NOT directly dependent on _____.

peptide bonds

What forms the backbone of a polypeptide?

peptide bonds

What kind of chemical bonds does the R-group orientation of polypeptides determine its shape?

peptide bonds

____ bonds link amino acids in proteins

peptide bonds

Primary Structure

peptide bonds(covalent bond) forms between a carboxyl group of one amino group and an amino group of its neighboring amino acid(adjacent)

What are bacteria cell walls composed of?

peptidoglycan

A nucleotide is composed of a(n)

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

Nucleic Acids are held together by what bond

phosphodiester bond

The lipids that form the main structural component of cell membranes are _____. ( Concept 5.3)

phospholipids

The lipids that form the main structural component of cell membranes are __________.

phospholipids

what are most membranes made up of?

phospholipids

The lipids that form the main structural component of cell membranes are _____. (eText Concept 5.3) * carbohydrates * triacylglycerols * cholesterol * proteins * phospholipids

phospholipids Correct. Phospholipids have a hydrophilic head and two hydrophobic tails. This permits the phospholipids to be arranged in a bilayer, or double layer, which forms a boundary between the cell and its external environment.

where do carbohydrates come from?

photosynthesis, carbon dioxide and water put togeather

In addition to primary structure, BLANK and BLANK conditions can affect structure.

physical, chemical

Starch

plant polysaccharide minimally branched and unbranched forms used for fuel in plants

Dye injected into a plant cell might be able to enter an adjacent cell through __________.

plasmodesmata

Cell junctions in plant cells are called __________, and communicating junctions in animal cells are called __________.

plasmodesmata; gap junctions

Oxygen and Nitrogen present means?

polar uncharged

A BLANK is a long molecule consisting of many similar building blocks.

polymer

A BLANK is a long molecule consisting of many similar or identical building blocks linked by covalent bonds.

polymer

Hydrolysis is breaking down a BLANK

polymer

Cellulose is a _____ made of many _____.

polymer ... glucose molecules

Cellulose is a _____ made of many _____. ( Concept 5.2)

polymer ... glucose molecules

Cellulose is a _____ made of many _____. (eText Concept 5.2) *polymer ... glucose molecules * carbohydrate ... fatty acids * lipid ... triacylglycerols * protein ... amino acids * polypeptide ... monomers

polymer ... glucose molecules Correct. Cellulose is a polysaccharide and therefore a polymer, constructed from many monosaccharide glucose monomers.

in a hydrolysis reaction, _____, and in this process water is _____. (eText Concept 5.1) * a monomer is broken up into its constituent polymers ... produced * monomers are assembled to produce a polymer ... produced * monomers are assembled to produce a polymer ... consumed * a polymer is broken up into its constituent monomers ... produced * a polymer is broken up into its constituent monomers ... consumed

polymer is broken up into its constituent monomers ... consumed In hydrolysis water is utilized as a reactant; water is not a product of a hydrolysis reaction.

Carbohydrate macromolecules are polysaccharides, BLANK composed of many sugar building blocks.

polymers

Lipids are the one class of large biological molecules that do not form BLANK

polymers

Three of the four classes of macromolecules—carbohydrates, proteins, and nucleic acids—form chainlike molecules called BLANK.

polymers

Alpha- glucose

polymers form helical structures like starch

Beta- glucose

polymers form straight structure like cellulose

Quaternary structure results when two or more BLANK chains form one macromolecule.

polypeptide

Beta Strands

polypeptide chains that are almost fully extended stabalized by hydrogen bonds between C=O and NH on adjacent strands

A functional protein consists of one or more BLANK precisely twisted, folded, and coiled into a unique shape.

polypeptides

polymer of amino acids?

polypeptides

DNA carries the instructions for building _____, and these instructions are found in informational units called _____.

polypeptides ... genes

What is a polypeptide, and how is it different than a protein?

polypeptides are "many peptides", polymers that contain 50 or more amino acids

A carbohydrate yields many monosaccharides when hydrolyzed is a ______.

polysaccharide

What are the polymer of carbohydrates?

polysaccharides

polymer of sugar?

polysaccharides

Stomata

pores on the leaf where O2 exits and CO2 enters

bases have what kind of charge

positive

It is hard to predict a protein's structure from its BLANK structure.

primary

______ structure is the sequence of amino acids in a protein

primary

The structural level of a protein least affected by a disruption in hydrogen bonding is the

primary level.

How is primary protein structure different from secondary protein structure?

primary protein structure is the sequence of amino acids, and secondary protein structure is the formation of a-helices (colils) and b-pleated (folds) sheets

Building a Protein

primary structure secondary structure tertiary structure quaternany structure

What are the levels of protein structure?

primary, secondary, tertiary, and quaternary

Autotrophic

produce their organic molecules from CO2 and other raw material from the environment.

Autotrophs

produce their own organic molecules from CO2

Quaternary Structure

produced by interactions between multiple subuntis

Higher levels of organization result in the emergence of new blank.

properties

DNA directs synthesis of messenger RNA (mRNA) and, through mRNA, controls BLANK synthesis.

protein

Which of the following lists ranks these molecules in the correct order by size? ( Concept 5.4)

protein, sucrose, glucose, water

Which of the following lists ranks these molecules in the correct order by size? (eText Concept 5.4) * water, sucrose, glucose, protein * protein, sucrose, glucose, water * protein, water, glucose, sucrose * water, protein, sucrose, glucose * glucose, water, sucrose, protei

protein, sucrose, glucose, water Correct. In this case, the ranking is from largest to smallest.

Chaperonins are protein molecules that assist the proper folding of other BLANK

proteins

Diseases such as Alzheimer's, Parkinson's, and mad cow disease are associated with misfolded BLANK.

proteins

tertiary structures

proteins assume complex, three dimensional [ ] that determine the final configuration of the polypeptide, the most important influence on this is its cellular environment - whehter its in the watery cytoplasm of a cell, in the lipids of cellular membranes or spanning a cell membrane, thus straddling two environments

Besides water, most of the mass of a typical cell is present in the form of one of these four categories of macromolecules: _____.

proteins, nucleic acids, carbohydrates, and lipids

Bilogical Macromolecules

proteins, nucleic acids, carbohydrates, lipids

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

proteins, nucleic acids, polysaccharides, and lipids

adenine

purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA

What causes carbohydrates to form into a ring?

putting them in water

_____ structure is the result of two or more protein subunits assembling to form a larger, biologically active protein complex

quaternary

proline

rarely forms intermolecular interactions just there for protein structure

Hydrolysis

reaction that breaks a polymer to release one or more monomers

Which of the following does not occur during the Calvin cycle? release of oxygen regeneration of the CO2 acceptor oxidation of NADPH consumption of ATP carbon fixation

release of oxygen

Which process is most directly driven by light energy? creation of a pH gradient by pumping protons across the thylakoid membrane removal of electrons from chlorophyll molecules reduction of NADP+ molecules ATP synthesis carbon fixation in the stroma

removal of electrons from chlorophyll molecules

5' to 3'

replication, transcription, and translation are carried out in this direction

five carbon sugar

ribose is a ______.

Protein synthesis occurs on BLANK.

ribosomes

alpha helix

right-handed coiled or spiral conformation

Tropical Oils

saturated plant oils, found in plants found in tropical climates including; palm oil, palm kernel oil, coconut oil. They are useful in food processing because they are less susceptible to spoilage than are more unsaturated oils.

_____ 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

secondary

How is secondary protein structure different from tertiary protein structure?

secondary protein structure is the formation of a-helices and b-pleated sheets, and tertiary protein structure is the result from interactions between R-groups

The alpha helix and beta pleated sheet represent which level of protein structure?

secondary structure

The alpha helix and beta pleated sheet represent which level of protein structure? ( Concept 5.4)

secondary structure

The alpha helix and pleated sheet represent which level of protein structure?

secondary structure

the alpha helix and beta pleated sheet represent which level of protein structure? (eText Concept 5.4) * secondary structure * pentiary structure * tertiary structure * primary structure * quaternary structure

secondary structure

Which plant part uses fat?

seed

primary structure

sequence of amino acids

Polar Amino Acid Groups

serine thremine cysteine tynosine apargine glutamina

What is sickle cell anemia? What level of protein structure causes sickle cell anemia?

sickle cell anemia is a disease in which the red blood cells are formed into a crescent shape at low oxygen levels, and is a single change in a amino acid sequence the primary structure

saturated fat

single bond, solid at room temp, most animal fats

What kind of chemical bonds make a polypeptide flexible?

single bonds of peptide bonds

What do saturated fats have?

single bounds maximum number hydrogen atoms tend to solidify

pyrimidines

single ring

rRNA

site of protein synthesis

if fat is saturated should it be liquid or solid?

solid

Mesophyll

specialized for photosynthesis. In C3 and CAM plants, mesophyll cells are located between the upper and lower epidermis; in C4 plants, they are located between the bundle-sheath cells and the epidermis.

Most proteins probably go through several stages on their way to a BLANK structure.

stable

Animals that feed on plants, especially parts rich in starch, have digestive enzymes that can hydrolyze BLANK to glucose.

starch

In what polysaccharide form do plants store glucose to be available later as an energy source? (Concept 5.2)

starch

In what polysaccharide form do plants store glucose to be available later as an energy source? (eText Concept 5.2) * protein * starch * glycogen * cellulose * fatty acids

starch

The polysaccharide that you are most likely to have eaten recently is _____. ( Concept 5.2)

starch

The polysaccharide that you are most likely to have eaten recently is _____. (eText Concept 5.2) * glucose * starch * ribose * chitin * lactose

starch Correct. Starch is a storage polysaccharide found especially in certain plant tissues.

name polysacchrides

starch, cellulose, chitin, glycogen

an example of a polysaccharide

starch, glycogen, chitin

Galactose

stereoisomer of glucose

Cholesterol is a BLANK

steroid

The most biologically important lipids are fats, phospholipids, and BLANK.

steroids

What do fats do?

storage of energy and insulation protection

Use of carbs

store sugars for energy production

Fructose

structural isomer of glucose that is sweeter

chitin

structural material in anthropods and fungi

Carbohydrates can function in which of the following ways? ( Concept 5.2)

structural support and energy storage

Carbohydrates can function in which of the following ways? (eText Concept 5.2) * structural support * energy storage * information storage * enzymatic catalysis * structural support and energy storage

structural support and energy storage

Protein functions include BLANK support, storage, transport, BLANK communications, movement, and defense against BLANK substances.

structural, cellular, foreign

Strong covalent bonds called disulfide bridges may reinforce the protein's BLANK

structure

What are the polypeptides that requires more than one to become a functional protein?

subunit

examples of disaccharides

sucrose and lactose

name disacchrides

sucrose, maltose, lactose

What kind of molecule is glycerol?

sugar alcohol

The simplest carbohydrates are monosaccharides, or simple BLANK.

sugars

Carbohydrates include BLANK and the BLANK of sugars.

sugars, polymers

Polysaccharides, the polymers of BLANK, have storage and BLANK roles.

sugars, structural

The chemical group that helps stabilize protein structure is the __________.

sulfhydryl group (-SH)

_____ structure is achieved when a protein folds into a compact, three- dimensional shape stabilized by interactions between side-chains R groups of amino acids

tertiary

How is tertiary protein structure different from quaternary protein structure?

tertiary protein structure is the result from interactions between R-groups, and quaternary protein structure are subunits that is based on tertiary structure

The overall three-dimensional shape of a single polypeptide is called the _____.

tertiary structure

The overall three-dimensional shape of a single polypeptide is called the _____. ( Concept 5.4)

tertiary structure

The overall three-dimensional shape of a single polypeptide is called the _____. (eText Concept 5.4) * secondary structure * primary structure * tertiary structure * double helix * quaternary structure

tertiary structure

What hormones does Cholesterol create?

testosterone, estrogen, cortisone, petosterone

Evidence that supports the prokaryotic origins of mitochondria and chloroplasts are all of the following except __________.

that mitochondria and chloroplasts have multiple copies of linear DNA molecules associated with their inner membranes

Chemical bonds between which part of the amino acid creates tertiary structure?

the R-groups

psi

the _______ bond is between the alpha carbon and the carbonyl carbon.

For which of the following parts of a chemical reaction do enzymes lower the energy?

the activation energy, Ea

amino end

the end of a protein having a free amino group

carboxyl end

the end of a protein having a free carboxyl group. The carboxyl end is encoded by the 3' end of the mRNA and is the last part of the protein to be synthesized in translation.

What are amino acids?

the fundamental building blocks of proteins

DNA and mRNA differ with respect to

the kind of sugar they contain

Secondary structure

the localized folding and/or coiling of the primary structure of a polypeptide, resulting from hydrogen bonding between atoms of the polypeptide backbone

Triglycerides

the major form of lipid in food and the body,consist of three fatty acids attached to a glycerol molecule.

β-turn

the most common form) is characterized by (a) hydrogen bond(s) in which the donor and acceptor residues are separated by three residues ().

In a 1-4 glycosidic linkage, _____. ( Concept 5.2)

the number 1 carbon in one monosaccharide is bound to the number 4 carbon in another monosaccharide

In a 1-4 glycosidic linkage, _____. (eText Concept 5.2) * one monosaccharide is bound to four others * the number 1 carbon in one monosaccharide is bound to the number 4 carbon in another monosaccharide * there are four possible isomers of the structure * the number 1 carbon in one nucleotide is bound to the number 4 carbon in another nucleotide * one glycerol molecule is bound to four fatty acids

the number 1 carbon in one monosaccharide is bound to the number 4 carbon in another monosaccharide

The "primary structure" of a protein refers to _____.

the number and sequence of amino acids

beta sheet

the second form of regular secondary structure in proteins consisting of beta strands connected laterally by five or more hydrogen bonds

What level of protein structure creates a-helices and b-pleated sheets?

the secondary protein structure

The "primary structure" of a protein refers to ___.

the sequence of amino acids

The "primary structure" of a protein refers to _____. ( Concept 5.4)

the sequence of amino acids

the "primary structure" of a protein refers to _____. (eText Concept 5.4) * interactions among the side chains or R groups of the amino acids * the α helix or β pleated sheets * the sequence of amino acids * coiling due to hydrogen bonding between amino acids * the weak aggregation of two or more polypeptide chains into one functional macromolecule

the sequence of amino acids

Which of the following parts of an amino acid vary between different amino acids?

the side chain, or R group

What level of protein structure creates irregular contortions?

the tertiary protein structure

primary structure

the unique sequence in which amino acids are joined

One characteristic shared by sucrose, lactose, and maltose is that _____. ( Concept 5.2)

they are all disaccharides

One characteristic shared by sucrose, lactose, and maltose is that __________.

they are all disaccharides

One characteristic shared by sucrose, lactose, and maltose is that _____. (eText Concept 5.2) * they are all disaccharides * they are all indigestible by humans * they are all polysaccharides * they all contain fructose

they are all disaccharides Correct. A disaccharide consists of two monosaccharides joined together by a glycosidic linkage.

How do phospholipids and triglycerides differ?

they differ from triglyceride by polar head and usually have at least on unsaturated carbon

Chemically, how do R groups differ from each other?

they differ in size, shape, and interaction in water-nonpolar and polar

parallel beta sheet

this orientation is slightly less stable because it introduces nonplanarity in the inter-strand hydrogen bonding pattern

Triacylglycerol is a fat composed of...

three fatty acid molecules joined by ester linkages to one molecule of glycerol.

Fats are made up of what?

three fatty acids linked to one glycerol molecule; called triglyceride

tertiary structures

three-dimensional structure

The light reactions take place in the _________ and the Calvin cycle takes place in the _________. stroma; thylakoids thylakoids; stroma inner membrane; outer membrane chloroplasts; mitochondria mitochondria; chloroplasts

thylakoids; stroma Within the chloroplast, the light reactions take place in the flattened sacs called thylakoids and the Calvin cycle takes place in the thick fluid called the stroma.

Which of the following are pyrimidines found in the nucleic acid DNA?

thymine and cytosine

Which of the following are pyrimidines found in the nucleic acid DNA? ( Concept 5.5)

thymine and cytosine

Which of the following are pyrimidines found in the nucleic acid DNA? (eText Concept 5.5) * thymine and cytosine * guanine and cytosine * thymine and adenine * uracil and guanine * adenine and guanine

thymine and cytosine

Which of DNA bases are Pyrimidines?

thymine, cytosine

what nitrogenous bases are pyrimidines?

thymine, cytosine, uracil

What is the process by which DNA codes for RNA?

transcription

mRNA

transfer of genetic information

tRNA

transfers amino acids

What is the process by which RNA codes for the production of a protein?

translation

What is a three fatty acid tails attached to a hydroxyl of glycerol called?

triglyceride

Lipids

triglycerides, phospholipids, steroids- hydrophobic, made of hydrocarbons

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

true

True or false? Guanine and uracil are examples of nitrogenous bases

true

Disaccharides

two of more monosaccharides bonded together

Dehydration reaction

two or more monomers joined together, water is lost, produces polymers and large macromolecules

Quaternary Structure

two or more polypeptide chains form a functional protein-subunits. Ex. hemoglobin

Disaccharides

two sugars

Phospholipids

types of lipids whose structure includes a phosphorous atom. Makes up most animal cell plasma membrane.

Sterols

types of lipids with a structure composed of multiple chemical rings such as cholesterol which aide in many process of cellular activities including membrane structure,permeability, and fluidity. Ergosterol which is found mostly in fungi membrane and also serves a similar function and a provitamin for vitamin D2, and Beta sitosterol; a phytosterol;plant sterol

Alterations in pH, salt concentration, temperature, or other environmental factors can cause a protein to BLANK. This loss of a protein's native structure is called BLANK.

unravel, denaturation

A fatty acid containing at least two double bonds is called _____.

unsaturated

non-covalent interactions

van der waals, hydrogen bonds, ionic bonds, hydrophobic interactions

Tertiary Structure

various bonds form between the R-groups make disulfide bridges

denaturation

verb: denature) For a macromolecule, loss of its three-dimensional structure and biological activity due to breakage of hydrogen bonds and disulfide bonds, usually caused by treatment with excess heat or extreme pH conditions.

hydrogen bonds

very weak bonds; occurs when a hydrogen atom in one molecule is attracted to the electrostatic atom in another molecule

In a dehydration synthesis reaction, __________ is always formed as a by-product of the reaction.

water

The unifying feature of lipids is having little or no affinity for BLANK.

water

__________ is always involved in hydrolysis reactions.

water

Biologically important chemical groups include all of the following except __________.

water (H2O)

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

water molecules are produced as a polymer is formed from monomers

H-bond

weak and allow DNA to zip and unzip. Hold nitrogen bases together.

antiparallel beta sheet

what are antiparallel, and can be close on the protein

tertiary structure, quaternary structure

what are stabalized by the same non-covalent interactions and disulfide bonds

side chain interactions

what are the interactions that form the tertiary structure

Cell motility, which includes changes both in cell location and in the movement of cell parts, requires interactions of the cytoskeleton __________.

with motor proteins

Why would a phospholipid have one unsaturated fatty acid

you wouldn't want you membranes of cells to be solid immovable structure, you would want it to be able to move

Watson and Crick

• got Nobel prize for building a model of and describing the structure of DNA as a double helix• got Nobel prize for building a model of and describing the structure of DNA as a double helix