Unit 3: Biochemistry

Lesson 2- The Building Blocks of Life

ObjectivesA student should be able to …

1.Explain why carbon constitutes many biological macromolecules.

2.Know what elements comprise carbohydrates, lipids, proteins, and nucleic acids.

3.Name some examples of carbohydrates, lipids, proteins, and nucleic acids in living things.

4.Explain the functions of carbohydrates, lipids, proteins, and nucleic acids.

5.Demonstrate how indicators can be used to detect macromolecules in foods.

Organic Chemistry

Organic chemistry – branch of chemistry

that studies compounds containing carbon.

• organic compounds

Why is Carbon So Special?

• Four (4) valence electrons

• Can form up to four covalent bonds.

• Forms a wide variety of molecules– Straight chains– Branched chains– Rings

Straight molecules Branched chain molecules Rings

Macromolecules

Macromolecules are large molecules made by joining smaller molecules together.

Macromolecules are examples of ___________.

The _____________ are made up of smaller units called ______________ which are joined together by covalent bonds in a process called __________________.

polymers

polymersmonomers

polymerization

Organic Macromolecules

Four Groups of Organic MacromoleculesGroup name

Chemical Composition

Examples

Function in Living Things

Copy the following table into your notes and use it to take notes today.

Group Name: Carbohydrates

• Chemical composition: – carbon, hydrogen, and

oxygen – General formula (CH2O)n

• Examples:– Monosaccharides –

simple sugars• galactose, glucose,

fructose– Polysaccharides –longer

carbohydrates composed of monosaccharides joined together

• glycogen, starch, chitin, cellulose

Photo credit – Steven Berg

Function of Carbohydrates In Living Things

Two main functions:• Source of energy for living things

– Glucose – ready energy– Glycogen (animals) and starch (plants) are energy storage

molecules

• Structural molecules– Cellulose – support of cell walls in plants– Chitin – hard outer shell of shrimp, lobsters, some insects,

and some fungi

Monosaccharides PolysaccharidesGive structure

orStore energy

Group Name: Lipids

• Chemical composition:– largely of carbon and

hydrogen– General structure:

• Triglyceride• Three (3) fatty acids

joined to a glycerol “backbone”

Glycerol Fatty Acids

Chemical Composition:

Saturated and Unsaturated Fats

• Saturated – all carbons are single bonded to one another

• Unsaturated - at least one carbon-carbon double bond exists in a fatty

• Polyunsaturated – more than one double bond exits

Examples of Lipids

• Triglycerides– Fat - solid at room

temperature– Oil – liquid at

room temperature

• Waxes• Phospholipids• Steroids

Function of Lipids in Living ThingsFats & oils:

- energy storage- insulation- buoyancy

Waxes:- water repelancy- specialized structures

(i.e. honeycomb)Phospholipids:

- cell membranesSteroids:

- Hormones – testosterone and adrenaline

- Cholesterol

Group Name: Proteins

• Chemical composition: – composed of amino

acids– amino acids contain

hydrogen, carbon, oxygen, and nitrogen

– amino acids are joined by peptide bonds

• Examples:– Bones, muscle, skin,

tendons, ligaments, collagen, hair, blood,

Functions of Proteins• 15% of your body mass

• Human body contains about 10,000 different kinds of proteins

• Functions:– Provide structural support (bones)– Allow movement (muscles)– Transport substances inside the cells and between cells– Communicate signals within/between cells– Speed up chemical reactions (enzymes)– Regulate cell growth– Defend against disease/foreign substances (antibodies)

Hemoglobin

Protein Organization

Proteins have up to four levels of organization or “structures.”

• Primary structure – sequence of amino acids in the protein chain.

• Secondary structure – amino acids in a chain can be twisted or folded

• Tertiary structure – twists or folds of a single protein chain

• Quaternary structure – the specific three-dimensional arrangement of multiple amino acid chains in space.

Group Name: Nucleic Acids• Chemical composition:

– composed of monomers called nucleotides

– nucleotides contain hydrogen, carbon, oxygen, nitrogen, and phosphorus

• Examples:– DNA (deoxyribonucleic acid)– RNA (ribonucleic acid)– ATP (adenosine triphosphate)

• Function:– Store and transmit genetic

information