Nutrition Unit 3 Exam
What are the differences between amylose, amylopectin and glycogen? (strucutral)
- AMYLOSE- is a straight chained homopolymer of glucose alpha 1'-4' glucose. this means it is composed of all glucose molecules with the same kind of glycolosic bonds. (has anywhere between 50-300 glucose bound together) - AMYLOPECTIN- branched chain homopolymer of [glucose alpha 1'-4' glucose and with branches of glucose alpha 1'-6' of glucose] (may have 1000s of glucose molecules bound together) - GLYCOGEN- (storage form of carbohydrates in animals) including humans, same structure as amylopectin, but even more highly branched, not usually present in food
How do we digest, absorb and metabolize amylose (a component of starch)? - Please list the enzymes involved in digestion and indicate where in the GI tract they function. - Indicate the type of absorption and what is being absorbed. - List the metabolic pathways involved in the metabolism.
- Amylose is digested beginning in the mouth with salivary amylase converting amylose to maltose. This is incomplete. In the duodenum (1st part of the small intestine) pancreatic amylase finishes the digestion of amylose to maltose. Maltose is further digested in the duodenum to 2 glucose molecules with the help of maltase. - The glucose is absorbed by active transport (it requires a pump and ATP). - Glucose goes through the pathways: glycolysis, TCA (Krebs cycle) and Electron Transport Chain.
How do we digest, absorb and metabolize lactose? - Please list the enzymes involved in digestion and indicate where in the GI tract they function. - Indicate the type of absorption and what is being absorbed. - List the metabolic pathways involved in the metabolism.
- This process begins in the duodenum where a hydrolysis reaction is catalyzed by the enzyme lactase. - The type of absorption is active transport, by the use of ATP and a protein pump - This process goes through all three metabolic pathways including glycolysis, citric acid cycle, and the electron transport chain.
The following questions are the Essay Questions
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Match the following descriptions to their correct term.
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be able to identify which structure belongs to a carbohydrate, lipid, or a protein.
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Trans fatty acids, which are inadvertently made during partial hydrogenation of plant oils...
-are listed on food labels since, January 2006 as mandated by the FDA. -increase the levels of circulating LDLs (bad cholesterol). -decrease the levels of circulating HDLs (good cholesterol).
Some fat is necessary in our diets for
-to increase the palitability of our foods -as a carrier of fat solulable vitamins -to provide essiential fatty acids
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AMYLOPECTIN- amylopectin furthere breakdowns any left over starch that amylose could not and turnes the martrose or maltose (from amylose) into glucose it is found in many different starches
CONTINUED....describe differences in our digestion or use of each of them and where each of these substances is found in nature.
AMYLOSE- amylase is responsible for the breakdown of the starch molecule into maltotrose and maltose. it is found in plants in nature.
CONTINUED....As great as plant sources are, what special considerations are necessary for people who only use (vegans) or mainly use (vegetarians) plant sources to obtain their dietary protein? What benefit do animal sources of protein have that is lacking in plant sources
As far as including proteins into this diet, they suggest; Legumes (beans, lentils, peas, peanuts), nuts, seeds, soy foods (tempeh, tofu). Generally, animal protein sources also supply other important nutrients, including vitamin B12 and a type of iron called heme iron. this is more readily absorbed than non-hem iron found in plants
What are the differences between amylose, amylopectin and glycogen? Describe structural differences and where each of these substances is found in nature.
Both amylose and amylopectin are part of starch formed in plants.Amylose is a straight chain homopolymer of glucose held together by alpha 1'-4' glycosidic bonds. Amylopectin is a branched chain homopolymer of glucose held together by alpha 1'-4' and alpha 1'-6' glycosidic bonds. Glycogen is the storage form of glucose in animals (including humans) in liver and muscle it is a branched chain homopolymer of glucose held together by alpha 1'-4' and alpha 1'-6' glycosidic bonds.
how do we How do we metabolize any of the carbohydrates, lipids or proteins we've studied?
CARBOHYDRATES: cells get usable energy from these cells by 4 ways SMALL AMOUNTS OF ATP 1-) glycolosis 2-) pyruvate to acetylcoa 3-) cytric acid cycle LARGE AMOUNTS OF ATP 4-) electron transport chain
List the main component, origin, and role of each of the circulating lipoproteins: chylomicrons, VLDLs, LDLs, and HDLs.
CHYLOMICRONS: origin- endoplasmic reticulum in the entercytes of small intestine component- main central core of mostly triglycerides role- transporting dietary and cholesterol absorbed by intestinal eplithelium
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GLYCOGEN- glycogen is broken down to release glucose into the bloodstream to be used as fuel for the cells. glycogen is found in many different types of yeasts
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HDL's: origin- liver and intestine component- cholesterol, triglycerides, phospholipids and apoproteins role- transport cholestrol from non nepatic tissue to liver for excretion
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LDL's: origin- VLDL and IPL ini the plasma component- cholestrol and cholestrol esters role- deliver those types of cholestrol to perephreal tissues
Which of the following diseases are protein deficiency diseases?
Marasmus Kwashiorikor
Why are plant sources of protein emphasized in the Dietary Guidelines for Americans? What benefit do these sources provide that makes them better than animal sources?
They state that plant based diets are associated with lowering overall mortality and ischemic heart disease mortality, reducing medication needs, and reducing severity of high risk diseases like obesity, hypertension hyperglycemia, and even reversing type two diabetes. They contain two critical nutrients; fiber and phytonutrients
The circulating lipoproteins that are made in the liver, that carry triglycerides to "hungry cells" are called...
VLDL's
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VLDL's: origin- liver component-cholesterol, triglicerides, proteins, other fats role- carry triglycerides and other fats to your body
Match the following to make a combination of foods that will act as a complete protein source.
beans /rice hummus /pitta(flat bread) sesame seeds/ mixed bean salad peanut butter/ bread
Other names for glucose are
blood sugar/ dextrose
Which class of nutrient's primary role is to provide quick energy?
carbohydrates
How do we digest, absorb any of the carbohydrates, lipids or proteins we've studied?
carbohydrates: 1-) in the mouth salivarry amylase breakes down starches into shorter glucose chains 2-)when the food reaches the stomach the acid inactivates amylose and destroys the enzyme 3-)in the small intestin the pancrease amylase completes digestion of starches to maltose. other specific enzyes called brush border disaccarides break down disaccarides into monosacharides to be absorbed. 4-) once in the blood stream the momsaccaride travels to the liver. They convert fructose and galactose into glucose. The liver forms glucose into glycogen to bum for energy or release into bloodsteam for other body parts.
The type of lipoprotein that is mainly composed of triglycerides, that is made in our small intestine submucosa and circulate to provide triglycerides to cells that need the energy.
chylomicrons Chylomicrons are the lipoproteins made from the food we eat in our small intestine. They are mainly triglycerides, based on percent composition.
TRUE OR FALSE There are exactly 20 amino acids in a protein.
false
TRUE OR FALSE Primary structure of proteins is the 3-D structure stabilized by ionic bonds, covalent bonds, H-bonds, dipole-dipole forces, and London dispersion forces between side chains of amino acid residues.
false
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fat: the body must break down a triglyceride and fatty acid 1-) glycerol carries little energy and can be converted by the liver to pyruvate or glucose 2-) fatty acid hold most of the energy
Lipids that are solid at room temperature are called
fats Solid oils are fats
When increasing your __________ intake, it is important to also increase your intake of water.
fiber
Which of the following foods is the best source of omega-3 fatty acids for vegans?
flax seeds or walnuts
Food processors and manufacturers use amylopectin (modified food starch) to produce sauces and gravies for frozen foods because they
form a stable starch gel, which doesn't separate upon freezing and thawing.
the following represent a molecule that we would classify as a carbohydrate
glucose amylose glycogen sucrose lactose cellulose
Check all the following that are monosaccharides.
glucose ribose galactose fructose
What are the prefix and suffixes used to denote a sugar or carbohydrate?
glyco- -ose -saccharide
The storage form of (glucose) carbohydrate in animals (humans) muscle and liver is
glycogen.
Check all of the following that are functions of proteins in our body.
immunity carriers structure fluid balance speed up reactions
If a child is diagnosed with galactosemia the parents are advised not to breast feed. This is because mother's milk contains the sugar...
lactose
The main carbohydrate in human milk is...
lactose
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lipid: 1-) starts in the mouth by chewing and linguinal amylase begins breaking up fat. 2-) the intestinal cells absorb glycerol and storten to medium fatty acid chains to the blood streem 4-)micelles carry long chains of fatty acids and other products of lipid digeston into the intestinal villi 5-) intestinal cells package fatty substances into chleymicrons that travel down the lymp systen into the bloodstream
oil
liquid at room temperature
If no glucose is available from dietary carbohydrate, glucose in the blood may be derived from
liver glycogen, amino acids, odd chain fatty acids and glycerol.
Humans can generally digest a carbohydrate if the glucose bond between monomers is an alpha bond. Select all of the following carbohydrates that based on that criteria should almost always be digestible in humans.
maltose amylose amylopectin
You experience abdominal cramping after eating "fat-free" potato chips. The cause could be the ingredient
olestra
The scavenger pathway for LDL uptake is a means by which excess LDL contributes to ________________ in blood vessel walls which can lead to heart attacks or stroke.
plaque formation
DHA and EPA
polyunsaturated essential fatty acids
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protein: 1-)stomach acid unfolds protein exposing them to digestive enzyme. pepsin starts breaking down. 2-)in the small intestine the proteins break up the amino acids of the polypepsin. 3-)intestinal cells absorb amino acids and peptides. they also finish breaking the peptide into amino acids. amino acids are absorbed into cappilaries of the villi 4-) amino acids travel in the blood steam to tissues in need, the amino acids can be used by the liver in many different ways
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protein: are not a vital source of energy because of the unique shape. there main function is to serve as building blocks for synthesis of body protein and nitrogen containing compounds
trans fats
should be eliminated from the diet
saturated fatty acids
should be limited to 10% or less of daily caloric intake
fats
solid at room temprature
Molecules are classified as lipids based on their
solubility Lipids are not soluble in water, but are soluble in organic solvents
Be able to list the functions of proteins.
structure enzymes hormones antibodies receptors fluid balance carrier molecules
Check all of the following that are disaccharides.
sucrose lactose maltose
An important function of carbohydrates is to
supply energy
Mark all of the following that we should limit or avoid in our diet.
trans fats saturated fats
The main form(s) of lipid found in the food we eat is (are)
triglycerides
TRUE OR FALSE The secondary structure of proteins can be described as alpha helices or beta sheets. They are stabilized by hydrogen-bonds between amide groups.
true
After digestion and absorption, dietary carbohydrates may be
use for energy converted into glycogen and stored in liver and muscle tissue synthesized into fat
Which of the following is a complete protein source?
white meat/ chicken
Individuals with lactose intolerance can usually tolerate
yogurt and fatty cheeses.
