Macronutrients Carbohydrates

Inorganic vs. Organic Molecules  Inorganic:  Molecules that are not organic  Are generally simple and are not normally found in living things   Organic compounds:  Always contain CARBON and HYDROGEN  Can contain oxygen, nitrogen, phosphorus, or sulfur

Macronutrients vs. Micronutrients  What are the three nutrients that give you energy?  These three nutrients are called MACROnutrients  Your body needs a significant amount of these nutrients  MICROnutrients  Your body still needs these nutrients, but in smaller amounts  MICROnutrients do not provide energy

ESSENTIAL NUTRIENTS  Both macronutrients AND micronutrients are essential: meaning, your body needs them to function properly

Organic Molecules: Basic Structure Organic Molecules: Basic Structure What they are made of and how they are put together.  All the macronutrients we study in Nutrition have the same BASICS of structure  Are all organic (contain CARBON, HYDROGEN)  Are made up of one type of unit repeated many times (except lipids)

Macronutrients: Basic Structure  Single unit is called the MONOmer  “Mono” means “one”  Many monomers linked together makes a POLYmer  “Poly” means “many”

In other words…  Each MONOMER is BUILDING BLOCK in the structure of a POLYMER  Example: each brick in a brick house is a monomer. The house is the polymer.

Carbohydrates  Carbohydrates are an essential MACROnutrient: your body needs a lot of carbohydrates to function  Carbohydrates are organic: they contain Carbon, Oxygen, and Hydrogen  “ Carbo” = Carbon  “Hydrate” = water = H 2 O

Naming carbohydrates:  The GENERAL name for the MONOMER of carbohydrates is MONOSACCHARIDE  Mono = “one” and “saccharide” = sugar  The GENERAL name for the POLYMER of carbohydrates is POLYSACCHARIDE  Poly = “many” and “saccharide” = sugar

Naming Carbohydrates Cont…  Carbohydrates are recognizable by their -ose endings

Your mission:  To discover the common MONOMER of carbohydrates!

Discovery of the common monomer  Enzymes are specialized proteins that catalyze chemical reactions  In the simulated activity, an enzyme (specifically, lactASE) catalyzed the reaction that breaks down lactose, the sugar in milk

You are performing an experiment and get the following results. What happened? Explain these results in terms of monomers and polymers. SubstanceGlucose Test WaterNegative MilkNegative Milk + enzymePositive

Monomer? Polymer?  We were working with two sugars, lactose and glucose, trying to figure out which was which  When lactose was broken down, glucose is now present Lactose + enzyme  glucose + galactose Polymer + enzyme  monomer + monomer  Look at the other way: Monomer + monomer  polymer Glucose + galactose  lactose

Disaccharides & Polysaccharides  Di saccharides consist of two monosaccharides bonded together  Monosaccharide + Monosaccharide = Disaccharide = 2  Poly saccharides consist of MANY monosaccharides and/or disaccharides bonded together  Mono + mono + di + di = poly = 100 – 1,000’s

Further Classifying Carbohydrates  Monosaccharides and disaccharides are SIMPLE sugars  Polysaccharides, which are made of MANY simple sugars linked together, are called COMPLEX carbohydrates

Specific examples of carbohydrates  Monosaccharides  Examples: glucose (C 6 H 12 O 6 ), fructose, and galactose  Disaccharides  Examples: sucrose, lactose, and maltose

Specific examples of Carbohydrates  Polysaccharides  Examples: starch, pectin, cellulose, and glycogen

General Functions of Carbohydrates  Preferred source of energy for red blood cells, parts of the brain, & nervous system  If the carb is going to provide energy to drive other processes, what must happen?

Aerobic Cellular Respiration  General definition:  The process by which cells transforms energy (Glucose) into a usable form (ATP)  Is a series of three reactions: 1. Glycolysis 2. Krebs Cycle 3. Electron Transport Chain

Aerobic Cellular Respiration - General  Cellular respiration is the name for a series of reactions in which glucose is broken down into CO 2, H 2 0; ATP is “produced”

Essential Info  Structure and function of ATP  Cell and mitochondrial structure  Electron carriers

ATP  Adenosine tri- phosphate  Can be easily transformed to ADP (releasing energy) and back to ATP, making it an effective molecule for this process

ATP/ADP Cycle

Electron Carriers - Coenzymes Non-protein molecules that assist enzymes in biochemical reactions; carry electrons and hydrogen ions from one reaction to another NAD+  NADH (“carrying”) FAD  FADH 2 (“carrying”)

Bio Review: Cytosol  The fluid portion of the cell’s cytoplasm

Mitochondrial Structure

Glycolysis - General  Takes place in cytosol of the cell  Breaks down 6C glucose molecules into 3C pyruvic acid (pyruvate) molecules  Produces a net gain of 2 molecules of ATP (form of energy we can use), and 2 molecules of NADH

Between glycolysis and the Krebs Cycle…  3C pyruvic acid from glycolysis enters the mitochondria where additional steps prepare it to enter the Krebs cycle 1. Hydrogen atoms are stripped from pyruvic acid and transferred to NAD + 2. Carbon atom is stripped and lost as carbon dioxide The now 2C compound bonds to the carrier, CoA  now acetyl CoA (acetic acid)

Pyruvic Acid Becomes Acetyl CoA

Step 2: Krebs Cycle (also called Citric Acid Cycle): Mitochondrial Matrix  3C pyruvic acid from glycolysis loses a carbon molecule and becomes a 2C molecule called acetyl CoA  Acetyl CoA enters the Krebs Cycle  Bonds with a 4C compound oxaloacetate becoming 6C Citric Acid  During a series of steps, produces ATP, H ions, and electrons carried by NAD+ (now NADH) and FAD (now FADH 2 )  Carbon dioxide as waste

Pyruvic acid goes to the Krebs Cycle

The Electron Transport System - Inner Membrane  Electrons from glycolysis and the Krebs cycle enter the ETC  As the electrons move across a series of complexes in the membrane, hydrogen ions are pumped across the inner membrane (from matrix  intermembrane space)  At the end of the “chain” the electrons bond with hydrogen atoms & oxygen to form water

Anaerobic Respiration  If no oxygen is available, aerobic respiration can’t happen – no final electron acceptor  In anaerobic conditions, only glycolysis can take place – and this is called anaerobic respiration or lactic acid fermentation  We will come back to this process

Summary: Step 3, the ETC  Electrons from glycolysis and the Krebs cycle (carried by NAD+ and FAD) “fall” down a chain of complexes in the mitochondrial membrane  The energy from the electrons “falling” pumps H+ from inside the membrane to outside  Electrons and hydrogen combine with oxygen located at the bottom of the chain and form water (H20)

With the ETC…  On one side of the membrane is now an accumulation of hydrogen ions (H+)  The human body wants to be at equilibrium  After the ETC, there is a high imbalance of + charges (b/c of H + ) one side of a membrane (this is called a proton gradient)  The H+ ions “want” to diffuse back to the other side of the membrane and “even out” but the 2 nd mitochondrial membrane is preventing that

Chemiosmosis  Embedded in the membrane is an enzyme called ATP synthase  H+ ions flow through the ATP synthase to “even out” the charges on both sides of the membrane  As H+ ions flow through, their energy is used to make ATP from ADP and a P  This process is called chemiosmosis

The ETS / Chemiosmosis

ETS / Chemiosmosis- View #2

Animations  Electron transport: m/ETS.html m/ETS.html  Proton gradients and chemiosmosis: m/ATPmito.html m/ATPmito.html

Summary/Overview  Step 1: Glycolysis  Step 2: Krebs cycle  Step 3: Electron transport system/chemiosmosis

Cellular Respiration

Overall equation?  Glucose + oxygen  ATP + water + carbon dioxide Reactants: C 6 H , O2 Products: ATP, H20, CO2