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
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 = H2O
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.
Substance
Glucose Test
Water
Negative
Milk
Negative
Milk + enzyme
Positive
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


Disaccharides consist of two monosaccharides bonded
together
 Monosaccharide + Monosaccharide = Disaccharide
1
+
1
=
2
Polysaccharides consist of MANY monosaccharides
and/or disaccharides bonded together
 Mono + mono + di + di ++++++++ = poly
1 + 1 + 1 +++++++ = 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
(C6H12O6), 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 CO2,
H20; ATP is “produced”
Essential Info
Structure
and function of
ATP
Cell and mitochondrial
structure
Electron carriers
ATP


Adenosine triphosphate
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  FADH2 (“carrying”)
Bio Review: Cytosol

The fluid portion of the
cell’s cytoplasm
Mitochondrial Structure
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.
2.

Hydrogen atoms are stripped from
pyruvic acid and transferred to NAD+
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 FADH2)
 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 2nd
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:
http://www.sp.uconn.edu/~terry/images/ani
m/ETS.html
Proton gradients and chemiosmosis:
http://www.sp.uconn.edu/~terry/images/ani
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: C6H1206, O2
Products: ATP, H20, CO2