EXAM 2 STUDY GUIDE
Why are carbohydrates important to understand?
•Most of the foods you consume have some carbohydrates in them
–Exception: meats, fish, and eggs do not have any carbohydrates when you eat them.
•It is recommended that you consume 45-65% of your calories from carbohydrates.
•Carbohydrates are the preferred fuel source of many cells in your body.
● The most abundant monosaccharide in the human body is glucose. ● Which of the following are considered complex carbohydrate? Polysaccharides
Why does lactose intolerance cause pain?
● Low [lactase] in small intestine
● Improper lactose digestion
● Lactose is NOT broken down to galactose and glucose ● Lactose can’t be absorbed
● Lactose passes on to the large intestine
● Fermentation of lactose à gas, bloating & acidic stool
● Water remains in the large intestine with the lactose à diarrhea. ● PAIN!
★ Lactose intolerance is caused by an inability to produce enough lactase.
★ Where is lactase located in the body? Small intestine
★ There is fermentation in the mouth. This is why bad breath and dental caries (cavities) are often associated with a diet high in
carbohydrates.Don't forget about the age old question of What is the garcia effect?
★ Glycogen molecules found in humans are made entirely of glucose molecules bound together. True
★ WHERE DOES FERMENTATION OCCUR?
A.In the mouth
B.In the large intestine
C.In processing plants to produce yogurt
D.All of the above….. Fermentation can occur anywhere there is a carbohydrate loving bacteria and an available carbohydrate source
THE POLYSACCHARIDE STARCH
•Starch is the main sugar storage form for plants
•Starch is a polysaccharide
•It can also be said that starch is a complex carbohydrate that is composed of amylose and amylopectin. If you want to learn more check out What will be the insurance expense on the annual income statement for the year ended December 31, 2011?
•Starch can be easily broken down to its component glucose units
THE POLYSACCHARIDE FIBER
•Fiber is an indigestible polysaccharide
•Humans do not produce enzymes capable of breaking bonds between the glucose units
–However, large intestinal bacteria do produce enzymes capable of breaking bonds between glucose units!
● Glycogen can be found in the following foods:
D.All of the above contain glycogen
E.None of the above contain glycogen
–Many glucose units
•Glucose storage form in live animals
•Not found in food
–Glycogen phosphorylase aids in the breakdown between meals or during rigor
–Many glucose units
•Glucose storage form in plants
•Found in almost all plant foodstuffs
–Amylase aids in the breakdown in the mouth and SI Don't forget about the age old question of uh guest wifi
○ Many glucose units
○ Glucose linked together for structure
● Found in plant foodstuffs
○ We do not produce enzymes to digest fiber
○ Soluble fiber can be fermented by bacteria
Different types of fiber
•There are two types of fiber: insoluble and soluble fiber •Insoluble fiber:
–Is NOT water soluble
–Is NOT easily fermented
–Consists of cellulose, hemicellulose and lignin
–An example of a foods high in insoluble fiber is wheat bran •Soluble fiber Don't forget about the age old question of math 18a
–Is water soluble
–Is easily fermented (produces lots of gas)
–Consists of pectins, gums and mucilages
–An example of a food high in soluble fiber is oatmeal
If fiber cannot be digested by our bodies, why would we want to consume foods high in fiber?
•It is recommended that you consume 25-30 grams of fiber. •Fiber has many benefits.
–A feeling of satiety for longer following a meal
–Because fiber is not digested by your body, it contains little/no calories.
–It adds bulk to the diet which allows the digestive tract to ‘exercise’ while pushing along the indigestible carbohydrate
–It can help reduce blood cholesterol
How can I get enough fiber in my diet?
•Processing significantly changes the composition of our food.
–Generally, the more processed, the lower the fiber content of the food
–Choose foods that are ‘closer to nature’
–Eat the skins of your vegetables and roots!
If complex carbohydrates are made of sugar, why is it recommended that people consume complex carbohydrates…but avoid sugar?
•It comes down to a matter of digestion.
•It will take longer for your blood sugar to rise following a meal with complex carbohydrates compared to a meal high in simple sugars.
DIGESTION OF A BOWL OF MALTED CEREAL WITH A BANANA (sugar, starch and fiber)
Bread traveling to the liver
•The carbohydrates absorbed from the small intestine enter the blood. The liver converts, stores or repackages the carbohydrates.
•The small intestine can absorb ANY monosaccharide (including galactose and fructose)!
–Galactose and fructose aren’t used by the body
–Galactose and fructose are converted to glucose by the liver •Carbohydrates can be stored as glycogen!
–Bonds are formed between the glucose molecules to form glycogen
•Carbohydrates can also be converted to fat and stored on your hips, thighs and everywhere.
POLYSACCHARIDE -- GLYCOGEN
•Glycogen is polysaccharide storage form of glucose in the human body •Glycogen can be stored in both the liver and muscles
–Glycogen stored in the liver is used to regulate blood sugar •Glycogenesis following a meal
•Glycogenolysis between meals
–The muscles are selfish with glycogen. The glycogen stored in muscles is primarily used for work by the muscles!
•Glycogen is not found in foods
● Glucagon is released from the pancreas in response to low blood glucose levels.
Insulin: tells your body to take-up glucose
Glucagon: tells your body to release stored glucose
Your body wants to maintain a specific level of glucose in the blood.
To help maintain the optimum [blood sugar], your body uses the hormones insulin and glucagon and the processes glycogenesis and glycogenolysis.
What is diabetes? What does it have to do with CHO? •Problem with blood glucose regulation
•There are two types:
–Type I / early onset / insulin dependent / childhood diabetes (5% of all cases)
•Lack of insulin
•Early in life!
–Type II / adult onset / insulin independent / adult diabetes (90-95%) •Insulin produced
•Insulin receptor problem
•Often associated with obesity
WHAT DOES THE PANCREAS DO?
•What two vital functions does the pancreas perform? Keeps proper level of sugar in the blood, partially digest
•What do enzymes from the pancreas do? Break down food (monosaccharides etc)
•What is the role of insulin following a meal? Acts like a key to open cells so sugar can enter to give us energy
•When is glucagon released from the pancreas? Releases when sugar has been stored for awhile; when you haven't eaten for a period of time
•What is the role of glucagon? Help digest food, allows muscles and liver to release sugars
TYPES OF DIABETES
•What is the cause of type 1 diabetes? Insufficient insulin production from pancreas
•What is the cause of type 2 diabetes? Receptors that insulin bind to don’t work well/ don’t work at all
•A sign is something we can SEE with our eyes or MEASURE with an instrument (ex: temperature)
–What are some common signs of diabetes?
Losing weight without trying, urinating more than usual, dry skin, having sores that don’t heal
● Why do they occur?
● What is the physiology?
•Patients FEEL symptoms (ex: nausea)
–What are some common symptoms of diabetes?
frequently being tired, having blurry vision, tingling sensations in the hands, itchy skin
● Why do they occur?
● What is the physiology?
•What are the effects of high blood sugar on the eyes? Swell blood vessels/bleed, vision problems, blindness
•What are the effects of high blood sugar on the kidneys? Stop working, kidney failure
•What are the effects of high blood sugar on the nerves? Less blood reaches nerves, become damaged, tingling/ numb/ burning sensations, neuropathy
The term that indicates the potential rise in blood glucose caused by a food is Glycemic index
–Meat does not have any CHO!
–Beans have a lot of CHO
•Which food groups contain carbohydrate?
–What form are they contained?
★ What is the primary function of carbohydrate (CHO) in the diet? Provide fuel (energy / ATP) for cells
FATS / LIPIDS
What is a lipid???
•By definition, lipids are substances that do not dissolve in water. •Some common examples of lipids in our foods are:
What is scientific definition of ‘fat’?
•In its most accurate definition, the triglycerides (a type of lipid) referred to as ‘fat’ is solid at room temperature.
–Name some lipids that are solid at room temperature.
What is the scientific definition of an oil?
•Oils are triglycerides (a type of lipid) that are liquid at room temperature. –Name some lipids that are liquid at room temperature.
•Almost all of triglyceride digestion occurs in the small intestine with the assistance of: pancreatic lipase.
How are fats and oils similar?
•Both fats and oils are lipids (insoluble in water)
•They are both triglycerides made from a glycerol backbone with 3 fatty acids attached.
•The 3 fatty acids characteristics determine whether the lipid is solid at room temperature (fat) or a liquid (oil).
–In general, the more saturated the fatty acids, the more solid the triglyceride is at room temperature.
–In general, the more unsaturated the fatty acids, the more liquid the triglyceride is at room temperature.
What is a triglyceride?
•A triglyceride is composed of a glycerol and three fatty acids bound together.
–The glycerol is the backbone and the three fatty acids are attached.
•Triglycerides are the main lipid in the food we eat (they are found in fats or oils)
Which of the following foods have 95% of the lipid in the form of triglycerides?
All of the above have 95% of the lipid in the form of triglycerides
FATTY ACIDS CAN VARY FOUR WAYS
1. Number of double bonds
–Saturated / unsaturated
2. Type of bond
3. Location/placement of double bond
–Omega 6 and Omega 3
SATURATED FATTY ACIDS
•Long chain of carbons…all single bonds
–The more saturated a fatty acid, the more solid it is at room temperature.
NUMBER OF DOUBLE BONDS (UNSATURATED FATTY ACIDS)
•Fatty acids containing one double bond are monounsaturated fatty acids (MUFAs)
•Fatty acids containing two or more double bonds are polyunsaturated fatty acids (PUFAs)
–Essential fatty acids are PUFAs
Based on information presented in the book and PPT, which of the following an example of a PUFA?
Omega 3 fatty acid
Omega 6 fatty acid
Essential fatty acid
All of the above are PUFAs
What is a ‘trans fat’?
A trans fatty acid is a fatty acid which contains a ‘trans’ bond. –However, trans bonds are not found very often in nature –Primarily man-made
•MAN-MADE trans fatty acids are produced commercially through the process of hydrogenation.
How are trans fats made?
•Bubble hydrogen through an unsaturated fatty acid
–hydrogenating the fatty acid!
•The hydrogens bond to the carbons and the double bond becomes a single bond!
–The unsaturated fatty acid will become a saturated fat!
•But, those hydrogens can also leave again, and the double bond can reform.
–When the double bond forms again, the fatty acid can take on a different shape than we would be found in nature.
–The fatty acid can become a ‘trans’ shape.
Clear liquid partial hydrogenation → fully hydrogenated hard white Select microwave popcorns, pie crusts, etc. will have it as an ingredient
Benefits of hydrogenation
•There aren’t any health benefits to you as the consumer. •However, there are benefits to food products
–Longer shelf life
–Higher smoke point
–More solid at room temperature
–Better texture and flavor
Are ‘trans fatty acids’ bad?
•MAN-MADE Trans fatty acids are possibly the worst fatty acid for our health!
•MAN-MADE Trans fats are associated with an increase in the body’s production of ‘bad cholesterol’ (LDL)
How can we spot the MAN-MADE trans fats in food? •Looking at the ingredient list:
–Trans fats may be listed as:
•partially hydrogenated vegetable oils
•fully hydrogenated oil
•Looking at the nutrition facts panel:
–As of 2006, nutrient facts panels are required to state the grams of trans fat in a food.
LOCATION / PLACEMENT OF THE DOUBLE BONDS
•Triglycerides can be referred to with respect to the placement of double bonds (p. 146)
–Omega 3 fatty acids
–Omega 6 fatty acids
THE OMEGA FATTY ACIDS
•THE ESSENTIAL FATTY ACIDS:
–Linoleic – an omega 6 essential fatty acid
–Alpha-linolenic acid (ALA) – an omega 3 essential fatty acid –Eicosapentaenoic acid – an omega 3 essential fatty acid
REAL LIFE APPLICATION:
•What foods contain the essential fatty acids?
–Cold water fatty fish, like salmon
•Why would fish be recommended above other foods containing the essential fatty acids?
–The high concentration of essential fatty acids
–Adults should eat fish (like salmon) twice a week
•Short-chain fatty acids are usually liquid at room temperature while long-chain fatty acids are usually solid at room temperature. The
explanation for this difference is that chain length affects the “hardness” of a lipid.
FATTY ACID LENGTH AND SOLIDITY
•All other things being equal, the longer the fatty acid is, the more solid it is.
Is cholesterol a lipid, too?
•Cholesterol is also a lipid; however, it has a very different chemical structure.
–Cholesterol is classified as a sterol
•A sterol is a fused carbon ring structure composed of 4 fused carbon rings. LIPIDS CAN ALSO BE IN OUR BODY
LET’S BRIDGE THE GAP (lipids in food and body)
•Cholesterol can either come from your food or be made in our body and travels in the body as a component of lipoproteins.
–cholesterol is only found in animal products.
•meats, cheeses, eggs, butter, etc.
•IN OUR BODY:
–Your liver produces the cholesterol
•Even if you consume a vegan diet (free of animal products and cholesterol) you can still have high blood cholesterol
“Trans Fats Raise Blood Cholesterol”
…But, what are they talking about when they say “cholesterol”?
•Cholesterol is a lipid. It travels through the body as a component of a lipoprotein.
•Lipoproteins in the body are often referred to as “good cholesterol” or “bad cholesterol” to the general public
Does our liver produce “good” or “bad” cholesterol? •Our liver can produce BOTH
–beneficial lipoproteins or “good cholesterols” contain more protein and less cholesterol
–detrimental lipoproteins or “bad cholesterols” contain less protein and more cholesterol
…our genetics and our lifestyle determine how much of each we make
UNDERSTANDING BLOOD CHOLESTEROL
Total cholesterol (lipoproteins) ~ LDL + HDL
The GOOD vs the BAD
HDL - High Density Lipoprotein
•The good cholesterol contains fewer lipids, and is referred to as high density lipoprotein or HDL.
•Good cholesterol carries lipids from the tissues to the liver for processing. •Exercise is a great way to increase HDL!
LDL - Low Density Lipoprotein
•The bad cholesterol contains a lot more lipid than protein and is referred to as LDL or low density lipoprotein.
•Bad cholesterol carries lipids from the liver to the tissues (arteries can be affected!)
•Higher saturated and trans fatty acid consumption is associated with an increase in the production of bad cholesterol.
•The primary function of HDL is to
deliver fatty acids to the liver.
•Change your total lipid intake or your saturated fat intake with small changes
–Mustard instead of mayo
–Leave the cheese off
–Lower fat cheese options
–Dilute recipes with veggies
–Boxed cake? Substitute apple sauce for oil
–Skim milk vs. whole milk when cooking
–Egg beaters or egg whites instead of whole eggs
IMPORTANT ROLES OF LIPIDS
•Lipids in the food and fats in the body serve a very important purpose! •Lipids in the food
–Absorption of fat soluble vitamins
–Increase energy density of foods
•Lipids in the body
–Cushion vital organs
–Part of cell membrane
•Excess dietary fatty acids that are not required for energy production or other functions are
stored as triglycerides in adipose tissue.
What is the verdict on coconut oil?
•Coconut oil contains a lot of saturated fatty acids and may have positive or negative implications with respect to health. Although I see benefits over other saturated fatty acids….in my opinion, the jury is still out on where it ranks compared to other plant lipids.
What is a protein?
•Proteins are large, highly complex molecules composed of one or more chains of amino acids.
What are proteins composed of?
•Proteins are composed of amino acids
–There are 20 common amino acids
–Amino acids can link using a peptide bond
–2+ amino acids linked are referred to as a peptide
•There are dipeptides, tripeptides, and polypeptides
–Large peptides are called polypeptides
–Polypeptides in proper shape are functional proteins
What are amino acids?
•An amino acid contains:
–A central carbon atom linked to:
•An amine group (NH2)
•A carboxylic acid group (COOH)
•A side-chain (dependent on the amino acid)
Which is the order from smallest to largest?
Amino acid --dipeptide --tripeptide --polypeptide --protein
BUILDING A PROTEIN IN THE BODY
•Once the amino acids are absorbed into the bloodstream, inside cells they can be reassembled to make proteins needed by the body.
● A protein’s shape depends on its amino acid sequence. True If you notice from the image, there are red blood cells. One of the cells has a characteristic “sickle cell” shape. This sickle cell is due to a change in the DNA that causes amino acid production to be altered slightly. “The sickle cell trait provides a survival advantage over people with normal hemoglobin in regions where malaria is endemic. The trait is known to cause significantly fewer deaths due to malaria, especially when Plasmodium falciparum is the causative organism.” However, in areas where malaria is not a concern, the expression of the gene causes anemia and its associated signs/symptoms.
****8 FUNCTIONS OF PROTEIN IN THE BODY
1.Cell growth, repair, maintenance
2.Enzymes and hormones
3.Fluid and electrolyte balance
4.Maintain acid-base balance
7.Transport and storage of nutrients
8.Nerve function, blood clotting, wound healing
•When _____ production is reduced because of protein deficiency, _____ can result from fluid imbalance.
Fluid Balance in the Body With a Protein Deficiency •Marasmus
–Energy and protein deficiency
–Evil spirit that infects the first child when the second child is born
How much of my body is made of protein???
•Our body is made of approximately 15% protein by weight
•That is easy to remember, because it is recommended that adults consume approximately 15% of calories in the form of protein.
How do proteins differ when we compare them?
•We have many different proteins in our body and in our food
–As mentioned before, the sequence of amino acids and the shape of the protein determine the function of the body protein
–The ratio of amino acids in the food determine if it is a complete dietary protein
What foods are good sources of dietary protein?
–beef, chicken, and pork
–shrimp, fish, and crab
–skim milk, cheese, and yogurt
–soybeans, lima beans, and peanuts
–Pastas, breads, and cereals
How do most people meet their protein needs?
•Typical American consumed over 60% of their protein from animal meat or animal products (ex: milk or eggs)
–the trend still holds true today (NHANES)
•Most Americans eat significantly more protein compared to body needs.
Different Dietary Patterns
–Only fruits and nuts fallen off tree
–Anything that is plant based
–Any plants as well as milk and eggs
–Any plants, milk, eggs, and fish
–Only eats meat and organs
Do both plant food and animal food contain protein???
•YES! As stated before, both plant and animal foodstuffs can contain protein.
•However, there are fundamental differences
–Animal proteins are composed of ample amounts of essential amino acids in proportions that easily meet our protein needs.
–Animal proteins are easily digested
•They are more bioavailable
● Vegans have a difficult time meeting their protein needs False
Essential vs. Non-essential Dietary Amino Acids
•There are 20 amino acids that the body needs to function. •The 9 amino acids needed in the diet are ‘essential’ amino acids –It is essential that they are consumed in your food
–They are often referred to as ‘indispensable amino acids’
•The 11 amino acids that can be made in the body and do not need to be consumed in the diet
–They are often referred to as ‘dispensable amino acids’
–They can be made from essential amino acids
Which amino acids are essential?
•You can remember it by learning the acronym Private Matt Hill (PVT MT HILL)
Do all plant proteins lack essential amino acids?
•Almost all plant proteins lack one or more essential amino acids – exception SOY and QUINOA! Quinoa is a high protein grain.
–But, the amino acid that is lacking in most plant sources varies, depending on what the food is.
•A (limiting amino acid) is an essential amino acid that is lacking in a food. –It therefore, limits the body’s capacity to effectively produce body proteins.
Limiting amino acids in foods
–Contain a lot of isoleucine and lysine
–Lack enough methionine (and tryptophan at times)
•Therefore, methionine is the limiting amino acid!
–Contain a lot of methionine and tryptophan
–Lack enough isoleucine and lysine
•Most nuts and seeds:
–Lack enough lysine
–Lack enough methionine
● An example of protein complementation to make a complete protein
A.Lima beans and corn.
B.Rice and beans.
C.Hummus and pita bread.
D.All of the above are protein complementation.
E.The above are not but steak and eggs would be an example of protein complementation.
•Food sources that ‘complement’ each other with respect to the amino acid profile are referred to as complementary proteins
Calculating approximate protein needs of an individual
Needed grams of protein in a day
–0.8g per kg body weight
–0.36g per lb of body weight
•An example of a lightly active 220 lb male in nitrogen balance (protein equilibrium).
•How much protein does he need per day? 80g
The earlier calculated 80 grams is for protein equilibrium (nitrogen balance) •Nitrogen consumption = nitrogen excretion
WHO WOULD BE IN POSITIVE NITROGEN/PROTEIN BALANCE? A.Someone recovering from a serious burn
B.A growing child
C.An individual who had Kwashiorkor but now has a diet with ample protein
D.A person who donated plasma 2d ago and is now consuming a protein rich diet
E.All of the above would be in positive nitrogen balance
What happens if a person is in negative nitrogen/protein balance?
•Even if a person is not consuming adequate protein, the body still needs to produce enzymes that are made of protein.
•To get the needed amino acids to build enzymes, the individual will break down muscle protein.
–that individual is actually losing protein from the body faster than it is replaced!
Friends, going through life & changes in protein needs together What are her protein needs?
Friends, going through life & changes in protein needs together Lynn is was an Iron-Man triathlete (hypertrophy)
Julie was moderately active not gaining or losing muscle mass Lynn had a major illness/injury
From VERY active to sedentary
Julie is now recovering from donating plasma and Lynn is training again!
Protein in your foods
–Contains notable protein
–Poor source of protein •FRUITS:
–Poor source of protein •OILS:
–Contains significant protein •MEAT:
–Contains significant protein •LEGUMES:
–Contains significant protein