Studied by 7 people
What are carbohydrates composed of?
CHO
Types of simple sugars
monosaccharides
disaccharides
types of complex carbohydrates
oligosaccharides
polysaccharides
Example of a monosaccharide
glucose
fructose
galactose
sugar alcohols
pentoses
what monosaccharide is most abundant? where is it found?
glucose
blood sugar
what monosaccharide is the sweetest? where is it found?
fructose
fruit, honey, high-fructose corn syrup
How is lactose formed?
glucose + galactose
Where are pentoses found?
Ribose and deoxyribose
What do sugar alcohols do?
sweeten low or no-sugar foods
excess may cause GI upset
What are disaccharides?
2 monosaccharides joined together linked together by alpha or beta bonds
What determines if we can digest disaccharides
alpha bonds- digestible
beta bonds- indigestible
Examples of disaccharides, how they are formed, and where they are found
Maltose
glucose + glucose
seeds and alcoholic beverages
Sucrose
glucose + fructose
table sugar
Lactose
glucose + galactose
milk and milk products
What is an oligosaccharides
3-10 linked monosaccharides
examples of oligosaccharides and where they are found
raffinose and stachyose
onions, cabbage, broccoli, legumes
Are oligosaccharides digestible? why or why not
No, contain beta bonds
Examples of polysaccharides
Starch, glycogen, fiber
Examples of starches
Amylose and Amylopectin
Are starches digestible?
Yes
What is starch’s main function?
storage form of carbohydrates in plants
What is glycogens main function?
Storage form of carbohydrate in animals
storage is limited
Is glycogen digestible?
Not in our diet, but digestible
Is fiber digestible?
No
Examples of an indigestible fiber? and why it is indigestible
Cellulose, hemicellulose, lignin
we don’t have the enzymes to break beta bonds
Examples of soluble fiber
pectins, gums, mucilages, some hemicelluloses
Two types of fiber
Soluble and insoluble
Function of carbohydrates
provide energy
Which one of these contains whole grains?
Wheat flour/bread
Whole wheat flour/bread
Whole wheat flour/bread
Parts of a grain seed
Bran, endosperm, germ
What part of the grain seed do refined grains contain?
endosperm only
Two types of sweeteners
Nutritive and non-nutritive
What type of sweeteners provide energy?
nutritive
Examples of nutritive sweeteners
monosaccharides (glucose) and disaccharides, high-fructose corn syrup, sugar alcohols
Examples of non-nutritive sweeteners
saccharin
aspartame
sucralose
stevia
Functions of digestible vs indigestible carbs
Digestible
primarily serve as a source of energy
spare protein
prevent ketosis
Indigestible
improve bowel health
improve blood glucose control
reduce cholesterol absorption
reduce obesity risk
Starch digestion in mouth
salivary amylase breaks down polysaccharides into smaller polysaccharides and disaccharides
Starch digestion in stomach
No chemical digestion
Small intestine and pancreas do what in carbohydrate digestion and what do they secrete?
responsible for most carbohydrate digestion
pancreatic amylase (poly into smaller poly and di)
intestinal enzymes (di to mono)
enzymes that break down
maltose
sucrose
lactose
maltase
sucrase
lactase
Where are indigestible carbs broken down
large intestine where bacterial enzymes digest select fibers and produce short-chain fatty acids and gas
What monosaccharide(s) use active transport
glucose and galactose
What monosaccharide(s) use facilitated diffusion
fructose
Monosaccharides are transported through ______ and used by cells as a source of energy
bloodstream
Where is excess glucose stored?
as glycogen in the liver and muscles
also converted to fat and stored in fat cells
Primary vs secondary lactose intolerance
Primary
insufficiency of lactase production
Secondary
due to conditions that damage lactase producing cells in the small intestine
ex. Crohn’s disease
Lactose intolerance treatment
-up to 12g of milk at one time
-small amounts at a time
-yogurt and hard cheeses are low in lactose
-lactase products
Two parts of the body that regulate blood glucose
Liver and pancreas
What hormones does the pancreas secrete
insulin and glucagon
What hormone(s) decrease blood glucose levels
Insulin
What hormone(s) increase blood glucose levels
glucagon, epinephrine, norepinephrine, cortisol
Type 1 diabetes cause, risk factors, characteristics and treatment
-Autoimmune attack on the pancreas
-moderate genetic predisposition
-thirst, hunger, urination
-insulin
Type 2 diabetes cause, risk factors, characteristics and treatment
-More common (90% of cases)
-insulin resistance (pancreas still making insulin, cells don’t want insulin)
-strong genetic predisposition
-mild symptoms
-diet and exercise
Long-term complications of diabetes
cardiovascular disease
retinopathy- blindness
nephropathy- kidney disease
neuropathy- nerve damage
What is metabolic syndrome
cluster of health factors, diagnosed when 3 or more of the following criteria are present
large waist circumference
hypertension
elevated fasting blood fats
low HDL cholesterol
high blood glucose
3 groups in the diabetes prevention program
intensive lifestyle change group
metformin group
placebo group
Diabetes prevention program outcomes
after 3 years
lowered chances of type 2 diabetes by 58%
after 10 years
decreased by 34%
after 15 years
decreased by 27%
RDA for carbs
130 g/day
AMDR for carbs
45-65% of total kcal intake
AI for dietary fiber
25 g/day for women
38 g/day for men
DGA for added sugars
10% of total daily energy intake
Lipids composed of
CHO
Are lipids soluble in water?
No
Diglyceride meaning
Triglyceride that lost 1 fatty acide
Monoglyceride meaning
Triglyceride that lost 2 fatty acids
Hydrolysis definition
The reaction that releases fatty acids from glycerol
water is used
Condensation definition
The reaction that adds fatty acids to glycerol
Re-esterification definition
Process of reattaching a fatty acid to glycerol
Triglyceride structure
3 fatty acids attached to a 3-C glycerol backbone
How do fatty acids vary
number of carbons in the chain
degree of saturation
shape of chain
How many carbons are long-chain fatty acids and where are they found?
12+
beef, pork, plant oils
How many carbons are medium-chain fatty acids and where are they found?
6-12
coconut oil, palm oil, milk fat (butter)
How many carbons are short-chain fatty acids and where are they found?
<6
3% of fat in butter
Structure of a saturated fatty acid
all between carbon-carbon single bonds
saturated with hydrogen
Monounsaturated fatty acid structure and where they are found
one double bond in the chain
olive oil, almonds, peanuts
Polyunsaturated fatty acid structure, and where they are found
more than one double bond
sunflower oil, corn oil, safflower oil, fish oil
Shape of unsaturated fatty acids
bent
What does hydrogenation do?
adds hydrogen to the carbon chain of an unsaturated fatty acid
chain becomes saturated, straight, solid at room temperature
Omega-3 fatty acid structure
first double bond is between 3rd and 4th carob from the methyl group
Omega 6 fatty acid structure
first double bond is between the 6th and 7th carbon from the methyl carbon
name for omega 3
alpha-linolenic acid
name for omega 6
linoleic acid
Which fatty acids are solid at room temperature and associated with an increased risk of chronic disease
saturated
Which fatty acids are liquid at room temperature and associated with an decreased risk of chronic disease
unsaturated
Omega 3 turns into what?
Eicosapentanoic acid (EPA)
Docosahexanoic acid (DHA)
food sources for alpha-linolenic acid
walnuts, flaxseeds, hemp oil, canola oil, soybean oil, chia seeds
food sources for EPA and DHA
cold-water fish (salmon, tuna, halibut, sardines, mackerel)
where is cholesterol found
exclusively in foods of animal origin
Functions of triglycerides
concentrated and compact energy source
insulate and cushion organs
enable absorption/transport of some nutrients
linoleic acid turns into what
arachidonic acid
alpha-linolenic acid and linoleic acid are precursors to eicosanoids. what are eicosanoids?
substances that produce diverse hormone-like effects on the body
structure of phospholipids
glycerol backbone
2 fatty acids
phosphate group
What part of the phospholipid is hydrophilic? hydrophobic?
hydrophilic-head
hydrophobic-tail
Functions of phospholipids
cell-membrane component
emulsifier
Cholesterol is used to make what
sex hormones
active form of vitamin D
bile
cell membranes
cortisone
shell-covering chylomicrons
enzyme that breaks down lipids in the mouth and what it breaks down
lingual lipase
short and medium chain fatty acids
enzyme that breaks down lipids in the stomach and what it breaks down
gastric lipase
triglycerides to diglycerides and free fatty acids
The presence of lipids triggers what hormone in the small intestine
CCK
What does CCK do?
triggers the release of bile and pancreatic lipase
bile emulsifies fat
pancreatic lipase breaks down triglycerides to monoglycerides and free fatty acids
micelles are formed
What are lipoproteins used for
the hydrophobic nature of lipids requires use of transporter within the blood
what does LPL stand for
lipoprotein lipase
what does LPL do
hydrolyzes circulating triglycerides from chylomicrons and VLDL to free fatty acids and glycerol
