Lets’s refresh some concepts

Alexia luli

Chemical elements with biological importance

• There are 94 elements found in nature.

• Organisms are composed basically of 6 of them (99% of their tissues).

Atomic composition of 3 organisms

Elements Human Alfalfa Bacteria

Carbon 19.37% 11.34% 12.14%

Hydrogen 9.31% 8.72% 9.94%

Nitrogen 5.14% 0.83% 3.04%

Oxygen 61.81% 77.90% 73.68%

Phosphorous 0.63% 0.71% 0.60%

Sulphur 0.64% 0.10% 0.32%

CHNOPS total 97.90% 99.60% 99.72%

Chemical elements with biological importance

Organic Molecules

These molecules are also called MACROMOLECULES

They are usually polymers, long chains of similar subunits. The subunits are called monomers.

Monomer + monomer + monomer + monomer…

POLYMER

1. Carbohydrates2. Lipids3. Proteins4. Nucleic acids

There are 4 types of Organic Molecules

REMEMBER All of them have Carbon present!!! Plus oxygen and hydrogen.

Nutrients: chemical substance found in food that is used in te body.

Proteins

STRUCTURE Long chains of amino acidsAmino Acids are the subunits of proteins. (MONOMERS)

AcidAmine

There are 20 different types of amino acids found in proteinsEssential amino acids must be acquired in the diet;

nonessential amino acids can be synthesized by the body

The structure of a protein determines its function

The different properties result from variations in the structures of different R groups

Non essential aminoacids can be produced from others

Deficiency: When a person is not

getting enough nutrients, leading to health problems

Malnutrition: Imbalance in diet that

leads to one or more diseases.

(difference with deficiency is that sometimes malnutrition is caused by excess of a nutrient)

Protein deficiency

Kwshiokor disease

the body can't process part of a protein called phenylalanine (Phe). Phe is in almost all foods.

Phenylketonuria (PKU): a genetic disorder

If the Phe level gets too high, it can

damage the brain and cause severe

mental retardation.

PKU video

Quick genetics review

1. Is the disease sex linked or automosmal?

2. What are the chances of a child to be born with PKU if both parents are carriers?

Carbohydrates: Classification

Monosaccharides Disaccharides

Polysaccharides

Physical properties

Composition

Diagramatic representation

Main examples

MaltoseLactoseSucrose

GlucoseGalactoseFructose

StarchGlycogenCellulose

Lipids

• Lipids are the main non-polar component of cells. Mostly hydrocarbons— C and H

• They are used primarily as energy storage and cell membranes.

• 4 main types: 1. fats (energy storage), 2. phospholipids (cell membranes), 3. waxes (waterproofing)4. steroids (hormones).

LipidsTriglycerids:  are the main type of fat. A triglyceride is composed of 3 fatty acids attached to a molecule of glycerol.

Energy-storage molecules.

Fats store about twice as much energy per weight as carbohydrates like starch.Note

a fatty acid is joined to each of the three Carbons of Glycerol by CONDENSATION

LipidsFatty Acids: The lipid building blocks:

Composed of a long hydrocarbon chain with an acid functional group functional at one end.

The fatty acid chains are usually between 10 and 20 Carbon atoms long. The fatty "tail" is non-polar (Hydrophobic) while the Carboxyl "head" is a little polar (Hydrophillic).

Methyl group

or Omega

end

LipidsA range of fatty acids are found combined in fatty acids.

The commonest fatty acids the body uses are 16 to 18 C long.

The fatty acids present in the diet can be divided intro 3 distinct groups:

1.Saturated2.Monounsaturated3.Polyunsaturated

Lipids

Omega... ?!

Unsaturated fatty acids, can have cis- or trans- double bonds

Summing up...

Trans fats in California

Evaluating diets rich in fats...

Study the food label you brought to class…

Check the types of fatty acids present in it… then think and write down…

How many types of fatty acids can you find?

Is it healthy? Why?

Class work:

Vitamins and minerals

Can these be called nutrients? Check your definition!!!

Nutrient density comparator

http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter25/animation__b_vitamins.html

http://www.youtube.com/watch?v=JwPVibQ6_3Y

B Vitamin like B12

Principal source: Milk products Funtion: Require for the formation and regeneration of red blood cells, for nutrient metabolism and growth, nerve fuction and calcium absorption. Its deficiency causes pernicious anemia, poor appetite, weight loss, tiredness, depression and lack of balance.

Fibre in Diet

A2 Energy in human diets

0

500

1000

1500

2000

2500

3000

3500

4000

Carbs Protein Lipids

NutrientEnergy per mass/kJ

per 100 g

Carbohydrates 1760

Protein 1720

Lipids 4000Damon et al, 2007

Different sources of energy in different ethnic groups

Diets rich in certain nutrients

Dietary Component Possible Health Consequence

Excess carbohydrates

Weight gain, obesity, diabetes type II

Excess fat Weight gain, obesity, cardiovascular disease

Excess Protein Decalcified bones, liver and kidney failure

http://www.medmovie.com/mmdatabase/MediaPlayer.aspx?ClientID=65&TopicID=670 Diabetes II

http://www.medmovie.com/mmdatabase/mediaplayer.aspx?

Message=VG9waWNpZD01MzY7Q2xpZW50SUQ9NjU7VmVybmFjdWxhcklEPTE=-nFEbIz6gy6Q= Cardiovascular Disease

http://www.youtube.com/watch?v=MX_eKKYvrqU Excess Protein

Body mas index

Where would a person 100 kg and 2 meters tall fall?Is this always true?

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