MACROMOLECULES OF THE HUMAN BODY

TYPES OF MACROMOLECULES

Carbohydrates Proteins Lipids (Fats) Nucleic Acids

MACROMOLECULE 1: CARBOHYDRATES

Carbohydrates contain 3 elements: C, H, and O

These elements are found in a 1:2:1 ratio

Carbohydrate Carbo = Carbon (C) Hydrate = Water (H20) C H20 = C, H, and O in a 1:2:1 ratio

CARBOHYDRATES ARE COMPOSED OF RINGS OF CARBON, HYDROGEN, AND OXYGEN

CARBOHYDRATES: MONOSACCHARIDES

Monosaccharides Mono = one saccharide = sugar

Characteristics of a Monosaccharide Are the simplest sugars Are single ring structures Typically have a chemical formula C6H12O6

EXAMPLES OF MONOSACCHARIDES

Glucose

Glucose, fructose, and galactose are all monosaccharides with the chemical formula C6H12O6.

Isomer – substances that have the same chemical formula, but a different structural formula

EXAMPLES OF MONOSACCHARIDES

Deoxyribose (C5H10O4) and Ribose (C5H10O5) are not true isomers as they do not have the exact same chemical or structural formulas.

Can you find the difference in the structural formulas of deoxyribose and ribose?

How do you suppose deoxyribose got it’s name?

CARBOHYDRATES: DISACCHARIDES

Sucrose = table sugar

Lactose = milk sugar

Maltose = malt sugar (barley products)

DISACCHARIDE FORMATION

Disaccharides are the result of the connection of two monosaccharides by dehydration synthesis.

DEHYDRATION SYNTHESIS EQUATION

C6H12O6 + C6H12O6 = C12H22O11 + H2O

C12H22O11 + C12H22O11 = C24H42O21 + H2O

C24H42O21 + C24H42O21 = C48H82O41 + H2O

CARBOHYDRATES: POLYSACCHARIDES

Polysaccharides are the result of connection of many monosaccharides by dehydration synthesis.

The general formula for polysaccharides can also be represented as (C6H10O5)n where 40≤n≤3000

Examples of polysaccharides are starch (plants/energy), glycogen (animals/energy), cellulose (plants/fiber), and chitin (animals/fungi/protection)

POLYSACCHARIDES: STARCH

Starches are glucose polymers. Amylose starches consists of a linear chain of several hundred glucose molecules and Amylopectin starches are a branched molecule made of several thousand glucose units (every chain 24–30 glucose unit). Starches are insoluble in water. They can be digested by hydrolysis, catalyzed by enzymes called amylases. Humans and other animals have amylases, so they can digest starches. Potato, rice, wheat, and corn are major sources of starch in the human diet. The formation of starches are the way that plants store glucose.

POLYSACCHARIDES: GLYCOGEN

Glycogen is a polysaccharide that is found in animals and is composed of a branched chain of glucose residues. It is stored in liver and muscles.

POLYSACCHARIDES ILLUSTRATED

CELLULOSE

The structural component of plants are formed primarily from cellulose. Wood is largely cellulose and lignin, while paper and cotton are nearly pure cellulose. Cellulose is a polymer made with repeated glucose units bonded together. Humans and many other animals lack an enzyme to break these linkages, so they do not digest cellulose. Certain animals can digest cellulose, because bacteria possessing the enzyme are present in their gut. The classic example is the termite.

CHITIN

Chitin is one of many naturally occurring polymers. It is one of the most abundant natural materials in the world. Over time it is bio-degradable in the natural environment. Its breakdown may be catalyzed by enzymes called chitinases, secreted by microorganisms such as bacteria and fungi, and produced by some plants. Some of these microorganisms have receptors to simple sugars from the decomposition of chitin. If chitin is detected, they then produce enzymes to digest it by cleaving the glycosidic bonds in order to convert it to simple sugars and ammonia.

CARBOHYDRATES IN FOOD

FruitsVegetablesNuts

GrainsSeeds/NutsPasta

FUNCTIONS OF CARBOHYDRATES

Providing energy and regulation of blood glucose

Sparing the use of proteins for energy Breakdown of fatty acids and

preventing ketosis (use of cellular glycogen for energy)

Biological recognition processes Flavor and Sweeteners Dietary fiber

MACROMOLECULE 2: PROTEINS

Proteins contain the elements carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur

PROTEINS AND AMINO ACIDS

Proteins are composed of amino acids linked together by dehydration synthesis

AMINO ACIDS AND R-GROUPS

THE PEPTIDE BOND

POLYPEPTIDES VS. PROTEINS

Polypeptide is a single linear chain of amino acids bonded together by peptide bonds.

PROTEINS VS. POLYPEPTIDESProtein molecules consist of one or more polypeptides put together typically in a biologically functional way.

PROTEIN STRUCTURE

FUNCTIONS OF PROTEINS

Required for building and repair of body tissues (including muscle)

Enzymes, hormones, and many immune molecules are proteins

Essential body processes such as water balancing, nutrient transport, and muscle contractions require protein to function.

Protein is a source of energy. Protein helps keep skin, hair, and nails healthy. Protein, like most other essential nutrients, is

absolutely crucial for overall good health

PROTEINS AS ENZYMES

The best-known role of proteins in the cell is as enzymes, which catalyze chemical reactions. Enzymes are usually highly specific and accelerate only one or a few chemical reactions. Enzymes carry out most of the reactions involved in metabolism, as well as manipulating DNA in processes such as DNA replication, DNA repair, and transcription.

PROTEINS IN FOOD

Red meat ChickenFishPorkEggsDairyBeans Nuts Seeds

MACROMOLECULE 3: LIPIDS

Lipids are also known as fat Lipids may contain the elements C, H,

O, N, P The main lipid consumed in

vegetable oil and animal fats is a triglyceride.

Triglycerides are composed of 3 (tri) fatty acids and one glycerol (glyceride).

TRIGLYCERIDE FORMATION: DEHYDRATION SYNTHESIS

FUNCTIONS OF LIPIDS

The main biological functions of lipids include energy storage and as structural components of cell membranes (phospholipids).

LIPIDS IN FOOD

MeatsDairyPastriesOilsDressingsProcessed foodsFast foods

MACROMOLECULE 4: NUCLEIC ACIDS

There are two nucleic acids: Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA)

Nucleic acids contain the elements C, H, O, N, P

NUCLEIC ACIDS AND NUCLEOTIDES

DNA and RNA are composed of nucleotides

Nucleotides are composed of a sugar, a phosphate group, and a nitrogenous base

DNA

DNA nucleotides are composed of the sugar deoxyribose, phosphoric acid, and one of four nitrogenous bases

The four nitrogenous bases of DNA are Adenine (A), Cytosine (C), Thymine (T), and Guanine (G)

Adenine forms two hydrogen bonds with Thymine

Guanine forms three hydrogen bonds with Cytosine

DNA

RNA

RNA nucleotides are composed of the sugar ribose, phosphoric acid, and one of four nitrogenous bases

The four nitrogenous bases of DNA are Adenine (A), Cytosine (C), Uracil (U), and Guanine (G)

Adenine bonds with Uracil Guanine bonds with Cytosine RNA is a single stranded molecule

DNA VS. RNA

DNA REPLICATION

In order for a cell to divide during the processes of mitosis (body cells) or meiosis (sex cells), the cell must first replicate (duplicate) it’s DNA.

TRANSCRIPTION: DNA TO RNA

Transcription: the process of making RNA from the DNA found within the nucleus of a eukaryotic cell

TRANSLATION: RNA TO PROTEINSTranslation: the process of making proteins from RNA within the cytoplasm of the cell

TRANSLATION: RNA TO PROTEINS

MONOMERS AND POLYMERS

MACROMOLECULE POLYMERS MONOMERS

Carbohydrates Polysaccharides Monosaccharides

Proteins Proteins/Polypeptides Amino Acids

Lipids Triglycerides/Phospholipids

Glycerol + Fatty Acids

Nucleic Acids DNA and RNA Nucleotides

Polymer: a large molecule (macromolecule) composed of repeating structural units

Monomer: a small molecule that may bind chemically to other monomers to form a polymer

MACROMOLECULES

DIGESTION OF MACROMOLECULES

In order for the human body to utilize the macromolecules it consumes in a meal, it must first break down the nutrients into their simplest form, monomers!

This process is achieved in the digestive system by way of enzymes

Once the macromolecules are broken into monomers they can be absorbed into the blood stream and transported to the cells where they will continue to perform their functions

DIGESTION, ENZYMES, AND HYDROLYSIS

Digestion is controlled by enzymes (specialized proteins) Enzymes are biological catalysts Catalysts initiate or speed up a reaction

without becoming part of the reaction Proenzymes – inactive enzyme precursor

Digestion is accomplished by hydrolysis Hydrolysis is the opposite of

dehydration synthesis

DIGESTION, ENZYMES, AND HYDROLYSIS

Hydrolysis: Hydrolysis is a chemical process in which a certain molecule is split (lysis) into two parts by the addition of a molecule of water (hydro).

One fragment of the parent molecule gains a hydrogen ion (H+) from the additional water molecule.

The other group collects the remaining hydroxyl group (OH−).

HYDROLYSIS OF TABLE SUGAR

THE PROCESS OF DIGESTION VIDEO

The Enzymes of Digestion (2:46) http://www.youtube.com/watch?v=AEsQxzeA

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DIGESTIVE ENZYMES

Carbohydrates

DIGESTIVE ENZYMES

Proteins

DIGESTIVE ENZYMES

Lipids and Nucleic Acids

Pancreatic nuclease enzymes digest nucleic acids (DNA and RNA) to nucleotides in the duodenum. Membrane-bound nucleotidase enzymes in the epithelial cells of the ileum digest the nucleotides to sugar, base and phosphate, which are absorbed.

ENZYMES IN ACTION

MICELLE

LACTEAL

CHYLOMICRONS

Lipoproteins: 85-92% triglycerides, 6-12% phospholipids, 1-3% cholesterol, 1-2% proteins