Download lecture6-BW

If you could peer into the crystal
ball and see how you were going
to die, would you do anything
different?
Lecture 6: Diabetes, sugar, and ATP
Objectives
Understand how sugar metabolism works
Understand how to make ATP
Understand where sugar comes from
Understand how sugar metabolism affects you
Key Terms
metabolism, gradient, equilibrium, phosphorylation, ATP, ADP
electron transport, glycolysis, insulin, glycogen, glucagon
NEXT WEEK:
Cell Division and Cancer
Leading Causes of Deaths
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Heart Disease: 700,142
Cancer: 553,768
Stroke: 163,538
Lung diseases: 123,013
Accidents (unintentional injuries): 101,537
Diabetes: 71,372
Influenza/ Pneumonia: 62,034
Alzheimer's disease: 53,852
Kidney Disease: 39,480
Septicemia (infection): 32,238
(Most current data available are for U.S. in 2001) www.cdc.gov/nchs/fastats/lcod.htm
I don’t have to worry about
that stuff till I get old!
All races, both sexes, 20–24 years
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Accidents (unintentional injuries)
Assault (homicide)
Intentional self-harm (suicide)
Cancer
Heart disease
Genetic abnormalities
Human immunodeficiency virus (HIV)
Stroke
Influenza and pneumonia
Diabetes
Relative to the
national population
of 20-24’s, are MSU
students less likely to
die from the top 3?
It’s difficult for one to
prevent bad luck, or
being a victim?
Two Types of Diabetes
Type 1
 Juvenile diabetes
 Autoimmune disease


Beta cells in pancreas
are killed by defense
responses
Treated with insulin
injections
Type 2
 Adults affected
 Insulin sensing system
impaired.
 Beta cells stop making
insulin.


Pancreas burns out
Treated with diet, drugs
Diabetes Mellitis



Cells in muscles, liver and fat don’t use insulin
properly
Disease in which excess glucose accumulates in
blood, then urine
Signs and Symptoms






Excessive urination
Constant thirst and or hunger
Fatigue
Weight loss
Blurred vision
Sores that don’t heal
Risk Factors








Age
Overweight
Inactive (exercise > 3x/week)
Family history: African, American Indian, Asian,
Pacific Islander, Hispanic or Latino descent.
Siblings or parents have diabetes
Gestational diabetes
Blood pressure over 140/90
HDL (good) cholesterol is low and triglicerides are
high
Reducing Risks


Physical activity- 30 min 5 days/week
Diet Modification
Low fat- 25% of calories max
 Low alcohol


Maintain Reasonable body mass
No crash diets
 Modify dietary intake

What, me worry?
 Myths:
 When
I leave MSU and get a job I will
have as much or more free time than I
do now. (I’ll still exercise as much as I do
now.
 I’m naturally healthy, I don’t have to
worry.
 I don’t have any risk factors so I’m
immune!
Diabetes Prevention Program
Program
Risk Reduction
 Healthy diet and exercise
58%
 Healthy diet and exercise (old folks) 71%
 Prevention drug
31%
 Control group (no change)
Participants were overweight, with high blood
sugar (Pre-Diabetes, impaired tolerance)
Question #1
Energy for metabolic processes only comes from
Sugar
A. True
B. False
Quick Anatomy Review
MOUTH(ORAL CAVITY)
IN
PHARYNX
ESOPHAGUS
STOMACH
LIVER
GALLBLADDER
SMALL INTESTINE
PANCREAS
LARGE INTESTINE (COLON)
RECTUM
ANUS
OUT
Absorption Mechanisms



Food is broken down to macro
molecules
Macro molecules are
disassembled by enzymes in the
intestines
Actively transported across
membrane:



Monosaccharides
Amino acids
INTESTINAL
LUMEN
Monosaccharides
(simple sugars)
carbohydrates
proteins
amino acids
EPITHELIAL
CELL
Nutrients diffuse from gut cells
into blood stream
INTERNAL
ENVIRONMENT
bile salts
bile salts
+
carbohydrates
proteins
EPITHELIAL
CELL
INTERNAL
ENVIRONMENT
FAT
GLOBULES
EMULSIFICATION
DROPLETS
MICELLES
CHYLOMICRONS
Control of Glucose Metabolism
insulin
Glucose is
absorbed
Glucose
uptake
Glucose to
glycogen
Glucose falls
Krispy
Kreme
Donuts (12)
Cells use
glucose
Glucose rises
Glycogen to
glucose
glucagon
Many cells, especially
muscle cells, take up
glucose and use it as an
energy source or convert it
to glycogen.
INSULIN
Beta cells of pancreas
release insulin into
blood.
Liver converts glucose
to glycogen, fats, proteins.
Blood glucose levels decline
to a set point; stimulus
calling for insulin
diminishes.
Stimulus:
Glucose is
absorbed
following a meal.
Stimulus:
Cells use or store
glucose between
meals.
Blood glucose levels
increase to a set point;
stimulus calling for
glucagon diminishes.
Liver converts
glycogen to glucose,
stops synthesizing
glycogen.
Alpha cells of pancreas
release glucagon into
blood.
GLUCAGON
IF YOU ARE LOST
CLOSE YOUR EYES
TILL UNTIL AFTER
THE NEXT SLIDE
Click to view
animation.
animation
Using Glucose
Skeletal Muscle Structure

A muscle is made
up of muscle cells

A muscle fiber is a
single muscle cell

Each fiber contains
many myofibrils
myofibril
Don’t Write This Down
Myofibril
A myofibril is made up of thick and thin
filaments arranged in sarcomeres
sarcomere
sarcomere
Z band
sarcomere
sarcomere
Z band
Z band
Don’t Write This Down
Sarcomere
A bundle of two types of microfilaments
Thin
Filaments
Thick
Filaments
Don’t Write This Down
Muscle Microfilaments
Thin filaments

Like two strands of
pearls twisted together

Pearls are actin

Other proteins in
grooves in filament
Thick filaments

Composed of myosin

Each myosin molecule
has tail and a double
head
Don’t Write This Down
Sliding-Filament Model
Sarcomere shortens because the actin
filaments are pulled inward, toward the
sarcomere center
Don’t Write This Down
Sliding-Filament
Model


Myosin heads attach
to actin filaments
Myosin heads tilt
toward and pull on
the actin.
Key Concept:
Each
head requires one
ATP for each pull!
There a lot of myosin
heads in a muscle
Muscle contraction
requires enormous
quantities of ATP!
Key Concept:
Contraction Requires Energy

Muscle cells require huge amounts of ATP energy
to power contraction

The cells have only a very small store of ATP

There are three pathways muscle cells use to get
ATP
Question #2
Cells burn insulin to make ATP
A. True
B. False
ATP for Contraction
ADP + Pi
Pathway 1
DEPHOSPHORYLATION
CREATINE PHOSPHATE
Relaxation
Contraction
creatine
Pathway 2
AEROBIC RESPIRATION
oxygen
Pathway 3
GLYCOLYSIS ALONE
glucose from bloodstream and
from glycogen breakdown in cells
What is ATP?
DEPHOSPHORYLATION!
RESPIRATION!
GLYCOLYSIS!
What’s ATP!
AND
How did we get here and where are we going
ATP Is Universal
Energy Source

Photosynthesizers get energy from the sun

Animals get energy second- or third-hand
from plants or other organisms

Regardless, the energy is converted to the
chemical bond energy of ATP
Making ATP

Plants make ATP during photosynthesis

Cells of all organisms make ATP by
breaking down carbohydrates, fats, and
protein
Two Main Pathways for
making ATP
Anaerobic pathways



FAST
Don’t require oxygen
Start with glycolysis in
cytoplasm
Completed in
cytoplasm
Aerobic pathways
SLOW
 Require oxygen
 Start with glycolysis in
cytoplasm
 Completed in
mitochondria
(Note: special membrane
and gradient)
Overview of Aerobic Respiration
CYTOPLASM
glucose
ATP
GLYCOLYSIS
energy input to
start reactions
e- + H+
(2 ATP net)
2 pyruvate
2 NADH
MITOCHONDRION
2 NADH
8 NADH
2 FADH2
e-
e- + H+
2
CO2
e- + H+
KREBS
CYCLE
e- + H+
ELECTRON
TRANSPORT
PHOSPHORYLATION
H+
4
CO2
2
32
ATP
ATP
water
e- + oxygen
TYPICAL ENERGY YIELD: 36 ATP
Overview of Aerobic Respiration
C6H1206 + 6O2
glucose
oxygen
6CO2 + 6H20
carbon
dioxide
water
Overview of Aerobic Respiration
CYTOPLASM
glucose
ATP
GLYCOLYSIS
energy input to
start reactions
e- + H+
(2 ATP net)
2 pyruvate
2 NADH
MITOCHONDRION
2 NADH
8 NADH
2 FADH2
e-
e- + H+
2
CO2
e- + H+
KREBS
CYCLE
e- + H+
ELECTRON
TRANSPORT
PHOSPHORYLATION
H+
4
CO2
2
32
ATP
ATP
water
e- + oxygen
TYPICAL ENERGY YIELD: 36 ATP
What’s the deal with Oxygen?
(electron transport chain over simplified)
Difficult to explain without
using lots of really cool
chemistry

Key concept: If you pull
water apart, it really wants
to get back together again

By giving the Oxygen
atom in water an electron,
it will give you a proton,
which is actually a H+

Oxygen is the final
electron acceptor?
How it Works:
1.
Pull a hydrogen off a water
(HOH to OH-)
2.
Pull the hydrogen (H+) across
a membrane (electrochemical
GRADIENT)
3.
Make the H+ do work on its
way back to OH-
http://www.sp.uconn.edu/~terry/images/anim/ETS.html

Question #3
More ATP is produced by the electron
transport system than is produced by
glycolysis
A True
B False
Coenzyme Production



Glycolysis
Preparatory
reactions
Krebs cycle
.

.
Total
2 NADH
2 NADH
2 FADH2
6 NADH
2 FADH
10 NADH
Key Concepts: Coenzyme production
1. Kreb’s cycle produces activated coenzymes
2. Coenzymes push electron transport
Making ATP:
Chemiosmotic Model
ATP
INNER
COMPARTMENT
ADP
+
Pi
ATP Synthase in Action
Key Points In Summary


Glucose eventually gets broken down
to carbon dioxide gas
Two ways to make ATP

Fast way - Anerobic
No oxygen required
 Glucose isn’t converted to CO2 but lactic
acid
 Only net 2 ATPs/glucose


Slow way - Aerobic
Requires oxygen
 Glucose converted to CO2
 Net 36 ATPs/glucose

Efficiency of
Aerobic Respiration

686 kcal of energy are released

7.5 kcal are conserved in each ATP

When 36 ATP form, 270 kcal (36 X 7.5) are captured in ATP

Efficiency is 270 / 686 X 100 = 39 percent

Key Concept: Most energy is lost as heat
Anaerobic Pathways

Do not use oxygen

Produce less ATP than aerobic pathways

Two types


Fermentation pathways

The burn

The Buzz
Anaerobic electron transport
Fermentation Pathways

Begin with glycolysis

Do not break glucose down completely to
carbon dioxide and water

Yield only the 2 ATP from glycolysis

Steps that follow glycolysis serve only to
regenerate NAD+
Lactate Fermentation
GLYCOLYSIS
C6H12O6
2
ATP
energy input
2 NAD+
2 ADP
2
4
NADH
ATP
energy output
2 pyruvate
2 ATP net
LACTATE
FORMATION
electrons, hydrogen
from NADH
2 lactate
Yeasts

Single-celled fungi

Carry out alcoholic fermentation

Saccharomyces cerevisiae


Baker’s yeast

Carbon dioxide makes bread dough rise
Saccharomyces ellipsoideus


Used to make beer and wine
MSU hard cider project: Sacchromyces banyan DV10
Alcoholic
Fermentation
GLYCOLYSIS
C6H12O6
2
ATP
energy input
2 NAD+
2 ADP
2
4
NADH
ATP
2 pyruvate
energy output
2 ATP net
ETHANOL
FORMATION
2 H2O
2 CO2
Animals Can’t
do this!
2 acetaldehyde
electrons, hydrogen
from NADH
2 ethanol
Anaerobic Electron Transport

Carried out by certain bacteria

Electron transport system is in bacterial plasma
membrane

Final electron acceptor is compound from
environment (such as nitrate), NOT oxygen
 Doesn’t
 Can’t
require Oxygen
work with Oxygen

ATP yield is low

Lets bacteria live where other organisms can’t
Question #4
Is Insulin a:
A. Carbohydrate
B. Protein
C. Lipid
D. Organophosphate
Energy Reserves




Glycogen is about 1 % of the body’s energy
reserve
Proteins is 21% of energy reserve
Fat makes up the bulk of reserves (78 %)
Note: In lecture 4 we discussed polysaccharides,
proteins and lipids.
Energy from Macromolecules




Carbohydrate
Glycogen
Protein
Lipids (fat)
bile salts
bile salts
+
carbohydrates
proteins
EPITHELIAL
CELL
INTERNAL
ENVIRONMENT
FAT
GLOBULES
EMULSIFICATION
DROPLETS
MICELLES
CHYLOMICRONS
Carbohydrate Breakdown
and Storage

Glucose is absorbed into blood

Pancreas releases insulin

Insulin stimulates glucose uptake by cells

Cells convert glucose to glucose-6-phosphate


Phosphate, functional group, phosphorylation
This traps glucose in cytoplasm where it can be
used for glycolysis
Making Glycogen

If glucose intake is high, ATP-making machinery
goes into high gear

When ATP levels rise high enough, glucose-6phosphate is diverted into glycogen synthesis
(mainly in liver and muscle)

Glycogen is the main storage polysaccharide in
animals
Using Glycogen

When blood levels of glucose decline,
pancreas releases glucagon

Glucagon stimulates liver cells to convert
glycogen back to glucose and to release it to
the blood

(Muscle cells do not release their stored
glycogen. This is their stored sugar!)
Key Concepts
Glucose Storage
1.
2.
3.
Glucose is used to make ATP first
When ATP store is full, glucose is stored
Glycogen is a big branched polymer of
stored glucose

Glycogen isn’t very soluble so it is trapped
inside the cell where it is stored.
Energy from Proteins




Proteins are broken down to amino acids and the
amino acids are broken down
Amino group is removed, ammonia forms, is
converted to urea and excreted
Carbon backbones can enter the Krebs cycle or its
preparatory reactions
Key Concept: Proteins can be used to make
ATP in Krebs Cycle
Energy from Fats (lipids)

Most stored fats are triglycerides

Triglycerides are broken down to glycerol and fatty acids

Fatty acids are broken down and converted to two carbon
blocks that enter the Krebs cycle (acetyl CoA)

Key Concept: Fatty acids are used to make ATP
.
Conversion is slow, 2C’s at a time
Before it can even enter Krebs Cycle
Processes Are Linked
Aerobic Respiration


Reactants
Photosynthesis

Reactants

Sugar

Carbon dioxide

Oxygen

Water
Products

Products

Carbon dioxide

Sugar

Water

Oxygen
Machinery of
Noncyclic Electron Flow
H2O
photolysis
e–
e–
NADP+
PHOTOSYSTEM II
PHOTOSYSTEM I
ATP SYNTHASE
NADPH
ADP
+ Pi
ATP
ATP Formation in Plants

When water is split during photolysis,
hydrogen ions are released into thylakoid
compartment. (Electrochemical GRADIENT)

More hydrogen ions are pumped into the
thylakoid compartment when the electron
transport system operates
ATP Formation

Electrical and H+ concentration gradient
exists between thylakoid compartment and
stroma

H+ flows down gradients into stroma
through ATP synthesis

Flow of ions drives formation of ATP
Two Important Pathways
Light Reaction
 Makes ATP from light
energy
Dark Reaction
 Makes glucose by
burning ATP
 Uses CO2 from the air
and water to make
glucose
Summary of Photosynthesis
light
12H2O
LIGHT-DEPENDENT
REACTIONS
2
ADP + ATP
Pi
6CO2
6O
NADP+ NADPH
PGA CALVIN- PGAL
BENSON
CYCLE
RuBP
P
C6H12O
6
(phosphorylated
glucose)
end product (e.g. sucrose, starch, cellulose)
Question #5
Carbon Dioxide Gas is used to build energy
storage molecules in the liver
A True
B False
Please hand your quiz sheet to
Andrea or Leah on your way out
Note: They will only accept one
answer form from each person
If you are interested in the first
extra credit project, please come to
the front of the class room