Biological moleculesLecture #2, Chapter 3

by John Cozza, Biology Dept.(some material modified from Raven, Biology 9th ed.)

Biological molecules outline

• Elements of life– Functional groups

• Overview of metabolism• Macromolecules– Carbohydrates– Nucleic acids– Proteins– Lipids

Biological molecules outline

• Elements of life– Functional groups

• Overview of metabolism• Macromolecules – Carbohydrates– Nucleic acids– Proteins– Lipids

Elements of life

(modified by JC)

Elements of life

Modified using info from: Nielsen, F. 1984. Ultratrace elements in nutrition. Ann. Rev. Nutr. 4:21-41

= form covalent bonds: biomolecules= monoatomic ions: osmosis & transport= trace elements*: specialized functions * There may be others!

Interactive question #1

The relative amount of iron, phosphorus, and sodium required in the human diet is

A.P > Fe > Na

B.P > Na > Fe

C.Fe > P > Na

D.Fe > Na > P

E.Na > Fe > P

Essential nutrients

• All life vs. some species

• Criteria– Found in cells– Deficiency

symptoms– Biochemical

function

Interactive question #2

Fluoride (F ion) is a candidate essential nutrient in humans. When tiny amounts are consumed in drinking water, F binds to the tooth enamel and has been shown to reduce cavities. This information is sufficient to confirm F as an essential nutrient.

A.True

B.False

Elements of life: the big six

Element Symbol Atomicnumber

Number of covalent

bonds

Polarity of bond with carbon

Hydrogen H 1 1 Non-polar

Carbon C 6 4 Non-polar

Nitrogen N 7 3 Polar

Oxygen O 8 2 Polar

Phosphorus P 15 3-5 Polar

Sulfur S 16 2 Non-polar

Carbon bonding• C – C bonding– Chains, branches, rings– Single, double, triple

• Hydrocarbons: C – C & C – H– Fossil fuels

• Added functions: N, O, P, S

Chlorophyll b

Biological molecules outline

• Elements of life– Functional groups

• Overview of metabolism• Macromolecules – Carbohydrates– Nucleic acids– Proteins– Lipids

Functional groups

Ethane(hydrocarbon)

Functional groups

Interactive question #3

Which functional group(s) does this molecule have?

A.Amino

B.Carboxyl

C.Hydroxyl

D.(A ) and (B)

E.(B) and (C)

Biological molecules outline

• Elements of life– Functional groups

• Overview of metabolism• Macromolecules – Carbohydrates– Nucleic acids– Proteins– Lipids

Metabolism

food macromoleculesbuilding blocks

(monomers)

Small compounds (H2O, CO2, NH3, etc.

structure

other biological molecules (vitamins, defense, hormones, pigments, etc.)

Catabolism (breakdown)

Anabolism(synthesis)

+ energy

costs energy

Synthesis and hydrolysis

(in anabolism) (in catabolism)

Biological molecules outline

• Elements of life– Functional groups

• Overview of metabolism• Macromolecules– Carbohydrates– Nucleic acids– Proteins– Lipids

Biomolecules table:Fill in using your book and other sources

Macromolecule How to distinguish

Building blocks

Examples(add more)

Functions

Carbohydrates disaccharidesstarch cellulose

Nucleic acids ATPDNARNA

Proteins enzymesmembranecollagen

Lipids triglyceridesphospholipidsterpenes

Biological molecules outline

• Elements of life– Functional groups

• Overview of metabolism• Macromolecules– Carbohydrates– Nucleic acids– Proteins– Lipids

Sugars: monosaccharides

Isomers in sugars

Sugars: disaccharides

http://hasquestions.tumblr.com/

Interactive question #4

This reaction is an example of ______, and it ______ energy.

A.Dehydration synthesis; gives off

B.Dehydration synthesis; requires

C.Hydrolysis; gives off

D.Hydrolysis; requires

Starch and cellulose

Biological molecules outline

• Elements of life– Functional groups

• Overview of metabolism• Macromolecules– Carbohydrates– Nucleic acids– Proteins– Lipids

Nucleotides

ATP molecule

N- base

phosphate groups

ribose sugar

Nucleic acids

https://www.idtdna.com/pages/decoded/decoded-articles/core-concepts/decoded/2011/03/16/unraveling-rna-the-importance-of-a-2'-hydroxyl

http://en.wikipedia.org/wiki/DNA

RNA

DNA

Biological molecules outline

• Elements of life– Functional groups

• Overview of metabolism• Macromolecules– Carbohydrates– Nucleic acids– Proteins– Lipids

Amino acid properties

• 20 regular• Nonpolar• Polar uncharged• Charged• Aromatic• Special function

Essential amino acids

• 8 out of 20• Traditional diets– Corn, wheat, squash

(high Met)– Beans (high Lys)– Potatoes (balanced)

Amino acids and the peptide bond

Protein primary

(1°) structure

—COO-Carboxyl end

Protein folding: 2° and 3° structure

2° structure

Hemoglobin

Protein structure: hemoglobin

Protein Data Bankhttp://www.rcsb.org/pdb/101/motm.do?momID=41&evtc=Suggest&evta=Moleculeof the Month&evtl=TopBar

David Goodsellhttp://news.rutgers.edu/focus/issue.2008-04-09.1171885477/article.2008-04-22.6247976497/articlepage.2008-04-22.8524051197

Biological molecules outline

• Elements of life– Functional groups

• Overview of metabolism• Macromolecules– Carbohydrates– Nucleic acids– Proteins– Lipids

Fatty acids

http://online.santarosa.edu/presentation/page/?48535

(MONO)

polar end

Are fatty foods bad for you?

African oil palmElaeis guineensis

http://www.eufic.org/article/en/nutrition/fats/artid/The-importance-of-omega-3-and-omega-6-fatty-acids/

*

*

Sources in the human diet:- Cold water fish (salmon, trout, tuna ,haddock, mackerel, sardines, cod)- Flaxseeds and flaxseed oil- Pumpkin seeds- Walnuts- Canola oil- Olive oil

Omega-3 and -6 fatty acids:essential!

Fats and heart disease

Estimated changes (% with 95% confidence intervals) in risk of coronary heart disease (CHD) associated with isocaloric dietary substitutions. Adjusted for coronary risk factors and total energy intake.

Hu, F. et al. 2001. Types of Dietary Fat and Risk of Coronary Heart Disease: A Critical Review. Am Coll Nutr 20 (1): 5-19

SC

UC

SU

TU(2%)

lowerrisk

higherrisk

Interactive question #5

According to this study, replacing some saturated or trans fat with unsaturated fat in the diet reduces the risk of heart disease.

A.True

B.False

Trans fatty acids

“partially hydrogenated vegetable oil” = trans fat =

BAD

cis unsaturated oils = GOOD

saturated fat = ?

http://www.indiana.edu/~oso/Fat/trans.html

Look at the ingredients!

Fats and cholesterol

Hu, F. et al. 2001. Types of Dietary Fat and Risk of Coronary Heart Disease: A Critical Review. Am Coll Nutr 20 (1): 5-19

total“bad”“good”

saturated translongsat

monounsat omega-6

higher

lower

Fats and oils: triglycerides

• 3 saturated or unsaturated fatty acids + glycerol

• Energy storage– Fats 9 Kcal/g– Starch 4 Kcal/g

• Average person weighs 100 lbs. less because of fat!

Saturated fat

______

Steroids cholesterol

sex hormones bile salts

metabolichormones

Phospholipids

Polar “head”

Prostaglandins

• Local hormones• Pain &

inflammation– Aspirin &

Ibuprofen

• Blood clotting • Smooth muscle

contraction– Labor

http://tonga.usp.edu/gmoyna/biochem341/lecture29.html

Terpenes

• Plant essential oils

• Antioxidants• Carotenes– Vitamin A

• Insect pheromones

http://www.chm.bris.ac.uk/motm/isoprene/isoprenejm.htm

Biological molecules summary

• Elements of life– Functional groups

• Overview of metabolism• Macromolecules– Structure– Function

Next:• Cells