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Nutrition
Why do we need to eat?
What do we need to eat?
What happens to food we eat?
Nutrition
Why do we need to eat?
energy
building blocks
macronutrients
micronutrients
calories
Macronutrients
carbohydrates
lipids (fats)
proteins
Micronutrients
vitamins, minerals
Carbohydrates
starches and sugars
most calories for most people
wheat, rice, oats, corn,…
Contain:
carbon, hydrogen, oxygen
Cn(H2O)n
Carbohydrates
building blocks are called:
monosaccharides
aka., simple sugars
e.g., glucose, fructose
Fig. 10-1
Carbohydrates
Put two -saccharides together:
disaccharide
e.g., lactose, sucrose, maltose
Carbohydrates
Put many -saccharides together:
glucose polysaccharides
cellulose
starch
glycogen
Carbohydrates
cellulose
plant, unbranched
starch
plant, branched
glycogen
animal, branched
All made from glucose
Why do we need glucose ?
ingestive heterotrophs
cellular respiration
glucose + O2
H20 + CO2 + ATP
energy
Macronutrients
carbohydrates
lipids
lipids (fats, oils, steroids)
molecules that do not
mix with water
made of hydrocarbon chains
non-polar
water is polar
O
+
H
H+
unequally shared
electrons
Some other molecules
are “polar” and will mix
well with water:
hydrophilic
Some molecules are not
polar (non-polar) and don’t
mix well with water:
hydrophobic
Some lipids are made from fatty acids:
Fig. 10-2
Some lipids are made from fatty acids:
fats and oils
Fig. 10-3
Some lipids are made from fatty acids:
fats and oils
Some are made from cholesterol:
Fig. 10-3
Some lipids are made from fatty acids:
fats and oils
Some are made from cholesterol:
steroids
cell membranes are made of:
phospholipids
Fig. 10-4
cell membranes are made of:
phospholipids
bilayer
Fig. 10-4
cell membranes are made of:
phopholipids
cholesterol
bilayer
Fig. 10-4
cell membranes are made of:
phopholipids
cholesterol
proteins
bilayer
Macronutrients
carbohydrates
lipids (fats)
proteins
Proteins:
building blocks are called:
amino acids (20)
e.g., glycine, valine
(8 are essential)
Fig. 10-5
Proteins:
Functions:
structure
collagen, keratin
transport
through membrane
Fig. 10-4
Proteins:
Functions:
structure
collagen, keratin
transport
through membrane
protection
antibodies
enzymes
DNA Polymerase
Fig. 10-7
Fiber
carbohydrate (cellulose)
not a source of calories
helps “move” stuff through gut
lower blood cholesterol
Micronutrients
Vitamins (table 10.2)
Micronutrients
Vitamins (table 10.2)
too much (bottom pp. 336 and 338)
too little
diseases
diseases
beri-beri
thiamine
a vital amine
vitamin
diseases
beri-beri
thiamine (B1)
scurvy
C
rickets
D
Micronutrients
Vitamins
Minerals
Na+, K+, Cl-, Ca++, iron, etc.
“vegetarian” vs. omnivore
meat-avoiders
meat-eaters
plants material are good sources for
most nutrients except:
balance of amino acids
vitamin B12
(cyanocobalamin)
Chapter 10
A.
Nutrition
Human nutritional requirements
– Macronutrients
Carbohydrates, Proteins, Lipids
– Micronutrients
vitamins and minerals
B.
Digestive system
– Anatomy and chemistry
– absorbing nutrients
– Cellular respiration
Digestion
chemical
breakdown food using
enzymes
vs
mechanical
physically break food
into smaller pieces
Digestion
Tube from mouth to anus
Fig. 10-8
Fig. 10-9
Chemical reactions:
enzyme
reactants
products
Protein digestion:
stomach
(stomach)
pepsin
protein
peptides
Protein digestion:
small intestine
(pancreas)
trypsin
protein
peptides
peptides
peptidase
(small intestine)
amino acids
blood
Absorption
from “gut” into body
some things diffuse
concentration
gradient
Fig. 10-11a
Absorption
from “gut” into body
some things are transported
facilitated
transport
Fig. 10-11b
Absorption
from “gut” into body
some things are transported
active
transport
Fig. 10-11c
Absorption
from “gut” into body
some large particles
are transported
endocytosis
(exocytosis)
Fig. 10-11d
Chapter 10
A.
Nutrition
Human nutritional requirements
– Macronutrients
Carbohydrates, Proteins, Lipids
– Micronutrients
vitamins and minerals
B.
Digestive system
– Anatomy and chemistry
– absorbing nutrients
– Cellular respiration
Production of energy
Remember cellular respiration?
Cellular respiration (includes Kreb’s cycle):
Glucose + O2
CO2 + H2O + ATP (energy)
Production of energy
cellular respiration
three subpathways
glycolysis
Kreb’s cycle
Electron transport chain
Fig. 10-12
Glycolysis
split glucose in half
pyruvate gets converted to acetyl-CoA
Other ways to make pyruvate/acetyl CoA
Glycolysis
in cytoplasm
Kreb’s cycle
in mitochondria
Fig. 10-12
Glycolysis
in cytoplasm
Kreb’s cycle
in mitochondria
Electron transport chain
in mitochondria
Fig. 10-13
Cellular respiration
Glucose
+
O2
CO2 + H2O
+
ATP (energy)
three subpathways
glycolysis
use glucose
Kreb’s cycle
make CO2
Electron
transport chain
use O2
make H2O
make ATP
Chapter 10
A.
Nutrition
Human nutritional requirements
– Macronutrients
Carbohydrates, Proteins, Lipids
– Micronutrients
vitamins and minerals
B.
Digestive system
– Anatomy and chemistry
– absorbing nutrients
– Cellular respiration
Chapter 10
C.
Nutrition
Circulatory system
– Anatomy
– distributing nutrients
– Cardiovascular disease
D.
Malnutrition and Poor health
Circulatory system
Blood
Fluid
(plasma; water, protein, ions, etc.)
Cells:
red blood cells
white blood cells
platlets
transport O2
immune system
blood clotting
Circulatory system
Vessels
arteries
carry blood from heart
veins
carry blood to heart
capillaries
exchange of materials
Fig. 10-14
Circulatory system
Heart
4 chambers
R + L atria
receive blood
R + L ventricles
pump blood
4 valves
2 AV valves
2 semilunar valves
Fig. 10-15
Circulatory system
Two circuits
systemic
O2-rich blood from left ventricle
out to the systems of the body
pulmonary
O2-poor blood from the right venticle
to lungs to exchange gases
internal
respiration
Figure 10.14
CO2
lungs
(air)
external
respiration
O2
internal
respiration
CO2
O2
cells
Aside on chapter 14 (respiration)
Fig. 14-1
internal vs. external respiration
Where do they occur ?
What happens there ?
alveolus
air
high O2
low CO2
low O2
high CO2
high O2
low CO2
external
respiration
cells/tissues
low O2
high CO2
high O2
low CO2
low O2
high CO2
internal
respiration
Back to chapter 10 (and the heart)
Circulatory system
Heart
Beats about 1/second
Signal to beat comes from within
pacemaker
Has its own blood vessels
coronary vessels
Cardiovascular Disease
Heart and/or vessels
number one cause of death/year
Risk factors:
gender
genetics
hypertension
Behavior:
smoking
diet (bad)
exercise (lack of)
stress
epidemiology
study of disease factors in
large populations
Austrailia
New Zealand
USA
Mediterranean
countries
high meat
intake
(saturated fats)
olive oil
(unsaturated fats)
high
incidence of
CV disease
lower
incidence of
CV disease
Japan
Japanese in
Hawaii or CA
low consumption
of saturated fats
lower
incidence of
CV disease
higher
consumption of
saturated fats
higher
incidence of
CV disease
These studies indicate that diet (fats)
is more of a factor than genetics
(heredity)
Atherosclerosis
Fat deposits in walls
of blood vessels
contribute to:
hypertension
heart attacks
Fig. 10-16
Lipid transport
Lipids-not soluble in H2O
Blood is mostly H2O
Carrier proteins in blood
HDL
high-density lipoprotein
LDL
low-density lipoprotein
Lipid transport
Lipids-not soluble in H2O
Blood is mostly H2O
Carrier proteins in blood
HDL
carry cholesterol from tissue
LDL
carry cholesterol to tissue
Lipid transport
Lipids-not soluble in H2O
Blood is mostly H2O
Carrier proteins in blood
(1)
HDL
“good”
ratio
(4)
LDL
“bad”
Malnutrition
“bad nutrition”
poverty
war
eating disorders
Malnutrition
Industrialized nations
obesity
too many calories
too much high-fat food
BALANCE
exercise
+
diet
increase
calories used
reduce calorie
intake
Malnutrition
Industrialized nations
obesity
anorexia nervosa
“When she weighed 65 kg (140 pounds),
Melanie thought of herself as fat and ugly.
Her menstrual periods stopped when her
weight dropped to 45 kg (100 pounds).
Now that she weighs 40 kg (90 pounds), all
her friends tell her she is too skinny, but
she is sure they are wrong because she
still thinks of herself as chubby. She wants
to lose even more weight. Melanie has an
eating disorder called anorexia nervosa.
Her body is not getting the nutrition it
needs. She could die the the situation
remains untreated.” (BT3, pg. 326)
Fig. 10-17
Malnutrition
Industrialized nations
obesity
anorexia nervosa
bulimia
BMI
body mass index
weight/height2
kg/m2
>=25
>=30
[
overweight
obese
weight/height2
pounds/inches2 x 703.7
]
Malnutrition
worldwide:
starvation
too many people
crop failure
political struggle
…
Chapter 10
A.
Nutrition
Human nutritional requirements
– Macronutrients
Carbohydrates, Proteins, Lipids
– Micronutrients
vitamins and minerals
B.
Digestive system
– Anatomy and chemistry
– absorbing nutrients
– Cellular respiration
Chapter 10
C.
Nutrition
Circulatory system
– Anatomy
respiration
chapter 14
– distributing nutrients
– Cardiovascular disease
D.
Malnutrition and Poor health