Nutrition, Digestion and Enzymes

You are what you eat!

ObjectivesTopic 30.2: Nutrition1. Explain how food provides energy.2. Identify the essential nutrients your body. 3. Explain how to plan a balanced diet.Vocabulary:Calorie Carbohydrate Fat

Protein VitaminMineral

Elements of Life

Organic Compounds

• Carbohydrates (sugars) : Carbon, Oxygen, Hydrogen

• Lipids (fats): Carbon, Oxygen, Hydrogen, and Phosphorus

• Proteins: Carbon, Oxygen, Hydrogen, Nitrogen, and Sulfur

• Nucleic Acids (DNA, RNA): Carbon, Oxygen, Hydrogen, Nitrogen, Phosphorus (not really food)

Nutrition

• Nutrient – substance that supplies energy and raw material for growth, maintenance, and repair.- water for all of life’s activities-carbohydrates for energy- fats (lipids) for cell membranes, hormones- proteins for enzymes, structures, transport- vitamins for working with enzymes to regulate body processes- minerals such as calcium/bones, iron/hemoglobin, sodium & potassium/nerve function

Calorie

• When food is burned, energy is converted to heat.

• Calorie= amt. of heat to raise the temperature of 1 g of H2O 1 degree Celsius

• c = 1 calorie C= 1,000 calories = kilocalorie• 1 gram of Carbohydrates = 4 Calories• 1 gram of Protein = 4 Calories• 1 gram of Fat (lipids) = 9 Calories

Water• Dehydration – abnormal depletion of body fluids• The major component of blood• Necessary for

– Electrolyte and pH balance – Transporting cells and O2

• Recommended amount – 8 glasses/day (64 ounces)

• 50-60% of body is water

Protein

• Second most abundant substance in humans• Key to every cell, antibodies, enzymes, and

hormones• Transport oxygen and nutrients• Role in developing/repairing bone, muscle, skin• Vital for human life

– May need additional protein if fighting off infection, recovering from surgery or blood loss, recovering from burns

Proteins• Amino acids

– Building blocks of protein • 20 essential amino acids must be obtained from food• 11 non-essential amino acids produced by the body

– Link together to form• Complete protein – supplies all essential amino acids• Incomplete protein – may lack some amino acids, but

these can be easily obtained from different sources• Few Americans suffer from protein deficiencies

Carbohydrates• Best fuel – provide energy quickly and

efficiently• Two types

– Simple sugars• Glucose (monosaccharide) – most common form• Fructose (monosaccharide) – found in fruits and berries• Sucrose (disaccharide) – sources include granulated

sugar, milk and milk products– Complex carbohydrates (polysaccharides)

• Starches – from flour, pasta, potatoes– Stored in the body as glycogen

• Fiber

Fiber• “Bulk” or “roughage”• Indigestible portion of plants• Insoluble

– Found in bran, whole-grain breads, most fruits and vegetables

– Found to reduce risk for several forms of cancer• Soluble

– Oat bran, dried beans, some fruits and vegetables– Helps lower blood cholesterol levels– Helps reduce risk for cardiovascular disease

Fiber• Offers many health protections

– Colon and rectal cancer– Breast cancer– Constipation– Diverticulosis– Heart Disease– Diabetes– Obesity

• Most American eat far less than recommended– Recommended is 20-30 grams and average is 12 grams

Fats• Also called lipids• Misunderstood but vital group of basic nutrients

– Maintain healthy skin– Insulate body organs– Maintain body temperature– Promote healthy cell function– Carry fat-soluble vitamins A, D, E, and K– Are a concentrated form of energy

• You should have ABOUT:• 50 grams of protein (20-25% of total Calories)• 50 grams of fat (20-25%)• 250 grams of carbohydrates (50-65%)Each day.But it depends on your total Calorie intake.

Fast Food Nutrition

• http://www.fastfoodnutrition.org/fast-food-restaurants.php

• What’s your favorite meal?• Is it nutritious?

ObjectivesTopic 30.3: Digestion4. Describe the organs of the digestive system.5. Explain what happens during digestion.6. Describe how nutrients are absorbed into the bloodstream and wastes are eliminated from the body.Vocabulary:Amylase Esophagus PeristalsisStomach Pepsin Small intestine

VilliLarge intestine (colon)

Digestion

• To break down food into simple molecules that can be used by body.

• Two types of digestion:- Physical (mechanical) digestion: Breaking down of food into smaller pieces.- Chemical digestion: Breaking down of macromolecules, polymers into smaller molecules.

Fig. 37-6, p.620

GALLBLADDER

Accessory Organs

SALIVARY GLANDS

PANCREAS

LIVER

MOUTH (ORAL CAVITY)

PHARYNX

ESOPHAGUS

STOMACH

LARGE INTESTINE (COLON)

RECTUM

ANUS

SMALL INTESTINE

Major Organs

Digestion-Anatomy

Identify

Digestion

• Mouth- Teeth tear apart food (physical digestion)- Saliva has an enzyme amylase to break down starches to complex sugars. (chemical digestion)

Digestion

• Esophagus moves food from mouth to stomach.• Smooth muscles contract to swallow food.• Contractions known as peristalsis.

Digestion

• Stomach continues mechanical and chemical digestion.

• Mechanical – Stomach muscles contract; mix & churn food; produce chyme.

• Chemical – HCl and pepsin (enzyme) work together to break down proteins into polypeptides.

DigestionAccessory Digestive Structures• Pancreas- produces hormones to regulate blood sugar; produces enzymes to breakdown carbohydrates, lipids, proteins. (chemical)• Liver produces bile which breaks down lipids (fats) to smaller molecules. • Gallbladder stores bile.

Digestion

• Small Intestine – 2 functions: complete chemical digestion and absorption of food molecules.

• Has 3 parts: duodenum, jejunum, ileum• Chemical digestion: All molecules broken

down to smallest component glucose, amino acids, fatty acids, glycerol

Digestion

Absorption of glucose and amino acids occurs at the villi (finger like projections). Absorbed by blood.Absorption of fats occurs at the villi; absorbed into lymph system.

Fig. 37-10a, p.624

intestinalmucosa

Fig. 37-10b, p.624

bloodcapillaries

lymphvessel

c one villusb villi on a mucosal fold

lymph vesselveinartery

vesicle

connectivetissue

villi (fingerlikeprojections ofmucosa coveredby epithelium

epithelium

Fig. 37-11, p.625

Complete Mechanical Digestion Chemical Digestion

Mouth

Esophagus

Stomach

Small Intestine

Digestion

• Large intestine functions: Remove water from undigested material; make vitamin K; expel waste from body.

Objectives

Topic 2.3: Carbon7. Describe the unique qualities of carbon.8. Relate the terms monomer and polymer.9. Describe the structures and functions of each of the four groups of macromolecules.Vocabulary:Carbon Lipid Protein

Nucleic Acid MonomerPolymer Carbohydrate

Organic Molecules

• Are made of carbon.• Can be very small like CO2 to very large like a

protein.• Living organisms are made of and use organic

molecules.

Carbon

• Is tetravalent; can form 4 bonds.• Bonds with many types of elements:

H,N,O,P,S• Can form many types of structures.

Macromolecules

• Macromolecule – Giant molecule made from smaller molecules.

• Polymer- Large molecule consisting of similar or identical molecules linked together.

• Monomer – Subunit of polymer.• Polymerization - Process of polymer creation

Polymerization

Figure 5.2 The synthesis and breakdown of polymers

Organic Molecules

• Carbohydrates, proteins, and nucleic acids are polymers (and macromolecules).

• Lipids are macromolecules (but not polymers)• All are biomolecules.

Carbohydrates

• Made of C, H, O in 1:2:1 ratio; (CH2O)

• Used for energy by all organisms, plants & some animals use them for structures.

• Monosaccharides- single sugar (monomer)

• Glucose is a monosaccharide used for energy.

Carbohydrates

• Disaccharides - Two sugars• Table sugar sucrose is a disaccharide

composed of two monosaccharides glucose and fructose (fruit sugar).

Carbohydrates• Polysaccharides are

polymers made of many monosaccharides.

• Examples:- Plant starch – used to store energy- Glycogen (animal starch) – used to strore energy.- Cellulose – used by plants for structure.

Cellulose

Lipids

• Made from C, H mostly.• Used to store energy, for cell membranes,

water proof coverings, some hormones.• Three types of lipids

- Triglycerides- Phospholipids- Cholesterol

Triglycerides

• Made of 2 components

- glycerol - fatty acid chains (3)

• Used to store energy (2x energy in a polysaccharide)

Saturated vs. Unsaturated

Saturated Lipid- •Single bonds between Cs in carbon skeleton.•Each C single bonded to H. (i.e. saturated with H) •Chain straight / pack tightly /solids at RT.Unsaturated Lipid – •Some Cs double bonded • Makes kink in chain • Chains can’t pack as tightly/ oils at RT.

Figure 5.11 Examples of saturated and unsaturated fats and fatty acids 

Saturated vs. Unsaturated

• Saturated fats - Animal fats - Raise LDL or bad cholesterol levels.

• Unsaturated fats-Vegetable fats - either help to raise HDL or good

cholesterol levels or decrease LDL levels.

CholesterolSteroids- lipids with 4 fused carbon rings.

Cholesterol is a steroid.

Function- component of animal cell membranes.

Precursor from which other steroids are made including hormones.

High levels contribute to atherosclerosis

Proteins

• Made of C, H, O, N• Have many functions:

- Control chemical reaction rates – Enzymes- Form bones and muscles – Structural- Hemoglobin carries oxygen – Transport- Fight disease - Antibodies

Proteins

• Are structurally diverse consistent with their many functions.

Proteins

• Amino Acids – Monomer

• There are 20 amino acids.

• Proteins are made by the bonding of some configuration of the 20 amino acids

Figure 5.16 Making a polypeptide chain

• There are 4 levels of protein structure:•Primary•Secondary•Tertiary•Quaternary

Objectives

Topic 2.4: Enzymes10. Explain how chemical reactions affect chemical bonds11. Describe how energy changes affect how easily chemical reactions will occur.12. Explain why enzymes are important to living things.Vocabulary:Chemical reaction Activation energyCatalyst Substrate Enzyme

Chemical Reaction

• Changes one set of chemicals into another set of chemicals.• Reactants- enter into chemical reaction• Products – produced by chemical reaction• Involves breaking and making of chemical bonds.

Energy

• Energy is released when chemical bonds are broken; reactions occur spontaneously.• Energy is absorbed when chemical bonds are formed; reactions require additional energy.• Living organisms carry out both types of chemical reactions to sustain life ; metabolism.

Enzymes

• Are catalysts; speed up rate of chemical reaction.

• Are proteins; biological catalysts.• Speed up reaction rates by lowering activation

energy.• Activation energy; the amount of energy

needed to get a chemical reaction started.• Lowering activation energy makes the reaction

happen faster.

Enzymes

Enzymes

• Enzymes provide site where reactants are brought together.

• Reactants = substrate• Substrate binds to active site of enzyme;

enzyme substrate complex• Reaction occurs.• Product released; enzyme freed for another

reaction.

Enzymes

Enzymes

• Enzymes are specific; enter into one type of reaction.

• Enzymes are biological molecules; can be damaged by changes in pH and temperature