AP bio ch. 3 TR

Test review for AP biology chapter three test

explain how dehydration reactions link glucose molecules to form polysaccharides

remove water molecules and form a covalent glycosidic bond between 2 glucose monomers.

sugar molecules = H2O -1

which macromolecule would incorporate radioactive sulfur and why?

It would be incorporated into proteins, sulfur is only found in proteins

(cys. and met. amino acids)

how many water molecules are required to hydrolyze a polysaccharide 10 monomers long?

9

(10-1=9)

Which functional group allows a molecule to act as a base, and why?

amino groups (NH2) because it accepts hydrogen ions (H+) to raise pH.

what role does cellulose play in plant cells

cell wall

identify the structure of a steroid and explain its biological function.

4-fused c-rings; component of the cell membranes signaling molecules that travel through the body.

during protein synthesis, to which functional group is the next amino acid added?

COOH

Carboxyl

which functional group is characterized of alcohols, and why?

hydroxly group (OH), H+ ion acceptors

which biological polymers contain nitrogen in their monomers?

nucleic acids, proteins, CHITIN!!!!!

How does testosterone and estradiol differ structurally and functionally?

functionally- Male vs. Female

Structurally- Different R / functional groups are different.

which bonds in certain molecules are always polar covalent, and why?

Any covalent bond between atoms of different elements are polar, because they have different electronegativities.

why are saturated fats solid at room tempurature?

Straight carbon chains allow the molecules to pack closely together.

Lack double bonds, keeps them solid.

give an example of a dehydration reaction in forming biological polymers.

The formation of a polysaaccride like starch from glucose monomers.

mono+mono—>disaccaride+H2O

give an example of a hydrolysis reaction in breaking down biological polymers.

breakdown of starch into individual glucose units

Disaccaride+H2O—> mono+mono

what is the primary function of RNA in cells?

translate genetic information from DNA into proteins

INFO FOR SYNTHESIS

which functional group would give a molecule a positive charge inside cells?

Amino Group

H2-N-C-?

why does lactase enzyme activity decrease when pH changes from 6 to 5?

pH disrupts hydrogen bonds

identify the carboxyl functional group and explain its role in biomolecules.

r-c=o

double-bonded C to O

what maintains the secondary structure of a protein?

hydrogen bonds that form between the amino and carboxyl group of the polypeptide backbone.

Where would hydrophilic vs. hydrophobic amino acids be located in globular protein?

hydrophilic SERINE amino acids are located outside

hydrophobic amino acids are on the inside

which molecule contains an amino groupsbut is not an amino acid?

NO CARBON 

H2-N-O-H

give an example of a biological monomer used to build polymers.

amino acids

why are lipids insoluble in water?

nonpolar hydrocarbons

If cells are grown with radioactive uracil, which macromolecule will be labeled?

RNA

how does hydrogenation change vegetable oil?

saturates the double bonds, raises the melting point

ex: fake butter, solid vegetable oil

What type of bond holds together the primary structure of a protein?

Covalent peptide bonds

If a supplement contains only C, H, N, and O, which macromolecule is missing?

nucleic acids

Why are unsaturated fatty acids usually liquid at room temperature?

DOUBLE BONDS within their hydrocarbon chains create “Kinks” or bends in their structure 

H on top of middle C

-C=C=C

which molecules in cells are typically ionized, and why?

they carry he+ electrical charge.

anything with a O-H

which functional group can act as a base, and how?

amino group

why do unsaturated fats have lower melting points than saturated fats?

double bonds prevent molecules from packing tightly together.

what type of carbohydrate is lactose?

Disaccharide

which molecules contain only no polar covalent bonds?

nonpolar covalent bonds of C surrounded by 4 H

    H

     |

H-C-H

    |

   H

How can oils be converted into solid fats?

hydrogenation removes double bonds

What geometric structure forms when carbon bonds covalently to four other atoms?

!!!!!!Tetrahedral geometric structure!!!!!

Compare dehydration reactions and hydrolysis reactions.

Dehydration reactions- build larger molecules from smaller ones

Hydrolysis reactions- break down larger molecules into smaller ones

Which drawing is missing a sulfhydryl?

Any one without R-SH

(R-S-H)

Identify a carbonyl functional group and explain its importance.

Its polarity makes carbonyl compounds reactive and capable of participating in many chemical reactions.

C=O at the end

why are saturated fatty acids common in butter and lard?

they are animal fats, and animals naturally produce fats that are high in saturated fatty acids

what three parts make up a nucletide?

1. phosphate group

2. 5 carbon sugar

3. nitrogenous base

where would hydrophilic amino acids be found in a protein?

the exterior of soluble proteins

Write the molecular formula of a polymer formed from 10 glucose molecules by dehydration.

C60 H102 O51

Which macromolecules would be labeled with radioactive phosphorus, and why?

Nucleic acids (DNA and RNA) and phospolipids

which carbohydrate includes all others (mono, disa, poly)?

carbohydrate

which structures cannot be formed by normal covalent bonding?

if they are held together with

1. ionic bonds

2. metallic bonds

3. a variety of weaker non-covalent intermolecular forces

what happens to water during peptide bond formation?

molecule of water is removed

based on amino acid sequence differences, how can scientists determine evolutionary relationships?

By comparing amino acid sequences of homologous proteins, such as cythochrome C, acrossdifferent species

what reaction mechanism links monomers into polymers in cells?

dehydration synthesis, condensation reaction

Which two functional groups are always found in amino acids?

The amino group and the carboxyl group

why are unsaturated fatty acids liquid at room temperature?

It has double bonding and double bonds don't let molecules squeeze together.