Review – Carbohydrates, Lipids, & Proteins

BiochemistryTHEME – Structure Dictates Function

Main Ideas

1)

2)

3)

structure

transmission of genetic info.metabolism

10.1 Introduction to CarbohydratesMono di oligo poly saccharides

10.1 Introduction to CarbohydratesGlucose:

___ C’s

aldehyde/ketone

Fructose

___ C’s

aldehyde/ketone

Stereoisomers# isomers = optionspositions

9.1 Review of Isomerism

10.2 MonosaccharidesRecognizing structural relations:For each of the following pairs of compounds, indicate whether the pair

consists of different compounds that are (1) constitutional isomers or (2) stereoisomers that are enantiomers or (3) stereoisomers that are diastereomers or (4) not isomers.

(a) D-Glucose and D-mannose

(b) D-ribose and D-xylulose

(c) D-fructose and D-arabinose

(d) D-sorbose and L-sorbose

(e) D-sorbose and D-fructose

(3) Diastereomers; they are stereoisomers that are not enantiomers

(1) Constitutional isomers; D-ribose is an aldopentose and D-xylulose is a ketopentose

(4) Not isomers; D-fructose is a hexose and D-arabinose is a pentose

(2) Enantiomers; they are nonsuperimposable mirror images

(3) Diastereomers; they are stereoisomers that are not enantiomers

10.3 Cyclic Hemiacetal Structures

Aldoses exist primarily as hemiacetals.

Fischer Projection

Haworth Projection

10.3 Cyclic Hemiacetal Structures

Ketoses exist primarily as hemiacetals.

Fischer Projection

Haworth Projection

10.4 Chem. & Phys. Prop. of Monosaccharides

Monosaccharides -

solubility in water ________________

phase at room temp. ________________

highly concentration solutions are ____________

solubility in alcohols ________________

solubility in ethers & hydrocarbons _______________

taste ________________

10.4 Chem. & Phys. Prop. of Monosaccharides

The Oxidation of the Aldehyde group/Benedicts TestAldose + Cu2+ carboxylic acid + Cu2O

-hydroxy ketones like fructose are converted to aldoses in the alkaline Benedicts soln, thus give a __________ test.

10.4 Chem. & Phys. Prop. of Monosaccharides

starch (a polymer) gives a ______________ test

Maltose (a disaccharide) gives a ___________ Benedict’s test.

,Linkages and Benedicts Test Review

Ch. 11-What you really need to know…

1) What is a lipid (recognize structure)?2) What is a fatty acid? (draw structure)3) Write the reaction for forming a triglyceride

and the saponification of a triglyceride.4) What’s the difference between a saturated

and an unsaturated fat? How does that relate to their m.p. and what phase they are at room temperature?

5)Fat soluble vs. water soluble vitamins?

Roles of BiomoleculesCarbohydrates & Lipids -

Proteins –

Nucleic Acids -

Provide energy, precursors to biomolecules, construct cell membranes

transmission of genetic info.

Catalytic, transport, regulatory, structural, contractile, protective, storage

Both Energy

fat 9.2 kcal/g carbs 4 kcal/g

Variety of roles due to complexity/diversity of structure in protein folding

KEY: Know structure of fatty acids and

triglycerides. The rest are simply “mostly

nonpolar”

11.2 Fatty AcidsFatty Acid -

Almost exclusively the linear (unbranched) acids with even #’s C’s

C=C almost always cis

11.2 Fatty AcidsTrans-fats?

11.3 The Structure and Physical Properties of Triacylglycerols

11.4 Chemical Reactions of Triacylglycerols

Hydrolysis:

Amino Acid Structure

12.2 The Zwitterion Structure of -amino acids

• amino acids can react with themselves to form a zwitterion

12.2 The Zwitterion Structure of -amino acids

• pH changes affect the structure of amino acids

12.3 PeptidesPeptide –

Polypeptide –

Protein –

peptide

formation:

a polyamide formed from amino acids linked by peptide bonds

a few to hundreds/thousands of amino acids

Usually 2+ polypeptides (along with other molecules or ions)

12.3 Peptides

12.5 The 3-D Structure of Proteins

Simple Protein –

Conjugated Protein

12.5 The 3-D Structure of Proteins

Levels of Structure

Primary (1º)

Secondary (2º)

Tertiary (3º)

Quaternary (4º) 3D relation among diff. proteins

Amino acid sequence

Conformation in a local region

When diff. 2 structures in diff. local regions interact

What gives rise to conformation stability1) Shielding of nonpolar amino acids from water

2) Hydrogen bonding between peptide groups

3) Attractive interactions between side groups of amino acids.

4) Attractive interactions of side groups of polar amino acids with water

5) Disulfide bridges

12.5 The 3-D Structure of Proteins3)Attractive interactions between side groups of

amino acids.

a. Hydrophobic attractions

b. Hydrogen bonding

c. Salt-bridge

4)Attractive interactions of side groups of polar amino acids with water

ex. globular proteins

fibrous proteins

12.5 The 3-D Structure of ProteinsWhat type of attraction would exist between side

chains of the following amino acids?

a)Pro-His

b)Ser-Tyr

c)Pro-Phe

d)Lys-Glu

e)Ser-Val

Positive Test ColorsTEST Positive Color

Iodine

Benedicts

Ninhydrin

Biuret

blue/black

red

blue

purple

For starch

For a-hydroxy aldehydes and ketones

For amino group on amino acids

For peptide group on proteins

Sudan III

Dissolves in nonpolar solvents (lipids)