1

Carbon, Macromolecules and

Carbohydrates

2

Elements Found in Living Organisms• Living organisms contain

many chemical elements, some in large quantities and some in very small amounts

• The 3 most common chemical elements of life are carbon, hydrogen, and oxygen (CHO)

• They are part of all the main organic compounds in living organisms

• Organic compounds:– contain carbon

– found in living organisms

• carbohydrates, lipids, amino acids are all organic molecules

3

4

Examples of Chemical Elements

and Their Roles

Element Role in Plants or Animals

Nitrogen Part of the amine groups of amino

acids and therefore proteins

Calcium Needed to make the mineral that

strengthens bones and teeth

Phosphorus Part of the phosphate groups in ATP

and DNA molecules

Iron Needed to make hemoglobin and

thus to carry oxygen in blood

Sodium Used in neurons (nerve cells) for

the transmission of nerve impulses

5

Organic Chemistry

• Study of carboncompounds

• Occur in more than just living things

• Are typically made by living things– Organic

compounds come from organisms

– The chemistry that you study in HS is inorganic• Compounds that

are found in the non-living world

http://www.chemistryland.com/ElementarySchool/BuildingBlocks/BuildingOrganic.htm

6

Organic Compounds• The molecules of many organic compounds are large and

may seem complex, but they are built up using small and relatively simple subunits

Fatty Acid

YOU MUST BE ABLE

TO IDENTIFY THESE

STRUCTURES, you do

not have to be able to

draw them.

7

Carbon Skeletons

• Vary in

– Length

– Branching

– Double bonds

– Rings

• Isomers have the same

molecular formula

• Isomers varying in their

structures

– Have different properties

http://fig.cox.miami.edu/~cmallery/255/255chem/p2x1.jpg

8

small organic molecules

larger organic molecules

COPY THIS ENTIRE CHART!

9

SUBUNITS

ex: sugars,

amino acids,

nucleotides

MACROMOLECULES:

ex: globular

proteins and RNA

MACROMOLECULE

ASSEMBLIES:

ex: ribosome

10

Condensation Reactions• In a condensationreaction, 2 molecules are joined together to form a larger molecule

• Water is also formed in the reaction

• For example, 2 amino acids can be joined together to form a dipeptide by a condensation reaction

• The new bond formed is a peptide linkage

• Further condensation reactions can link amino acids to either end of the dipeptide, eventually forming a chain of many amino acids

• This is called a polypeptide

www.pearsonsuccessnet.com activity 5.1 page 2

11

Condensation Reactions• In a similar way, condensation reactions can be used to

build up carbohydrates and lipids

• The basic subunits of carbohydrates are monosaccharides

• 2 monosaccharides can be linked to form a disaccharide and more monosaccharides can be linked to a disaccharide to form a large molecule a polysaccharide

12

three fatty-acid

tails

glycerol

triglyceride

+ 3H20

• Fatty acids can be linked to glycerol by condensation reactions to produce lipids called glycerides

• A max of 3 fatty acids can be linked to each glycerol, producing a triglyceride

13

Hydrolysis Reactions• Large molecules such as polypeptides, polysaccharides

and triglycerides can be broken down into smaller molecules by hydrolysis

• Polypeptides + water dipeptides or amino acids

• Polysaccharides + water disaccharides or monosaccharides

• Glycerides + water Fatty acids + glycerol

14

Monosaccharides

• glucose

• ribose

• deoxyribose

• fructose

• galactose

15

16

Disaccharides

DISACCHARIDE DESCRIPTIONCOMPONENT

MONOSACCHARIDES

SUCROSE COMMON TABLE SUGAR GLU + FRU

LACTOSE MAIN SUGAR IN MILK GALACTOSE + GLU

MALTOSE PRODUCT OF STARCH HYDROLYSIS GLU + GLU

CAN BE USED IN BEER FERMENTATION

17

• repeating, branching

macromolecule

• carb storage for plants

– For energy

– Cellulose

Starch

18

19

Glycogen

• storage of glucose in the liver and

muscle

– For energy

• animals only

20

Chitin• forms exoskeleton of

arthropods: insects, lobsters, shrimp, spiders

21

POLYSACCHARIDES

• STARCH energy storage in plants α-glucose

• CELLULOSE structure of plant cell walls β-glucose

• GLYCOGEN energy storage in animals α-glucose

• CHITIN structure of fungi cell walls & β-glucose

exoskeleton of insects

Polysaccharide Description Monomer Unit