KIN 275 Midterm 2 (Totosy v1)

What are some examples of visible fats?

Butter, margarine, oil, salad dressing, meat fat, chicken skin

What are some examples of invisible fats?

Meat fibres, milk, dairy products, nuts, eggs, baked goods

What is a lipid?

The chemical term for fat

What is a fat?

A group of organic molecules, most of which do not dissolve in water

What are some example of lipids?

Triglycerides, phospholipids, sterols

What is a Triglycerides?

Major form of lipid in food

Consists of three fatty acids attached to a glycerol molecule

What is the difference between fats and oils?

Fats are solid at room temperature

Oils are liquid at room temperature

What is Glycerol?

3 carbon chain with 3 OH groups

Water soluble

What does the type of fatty acid depend on?

Carbon chain length, Number of double bonds, and Location of said double bonds

Triglycerides are formed by ________ and broken down by __________.

Condensation, Hydrolysis

What is a glyceride with only 1 fatty acid called? 2 fatty acids? 3 fatty acids?

Monoglyceride, Diglyceride, Triglyceride

How does the length of carbon chain affect the created fatty acid? Which carbon chain length is most common?

<10 carbons = short chain fatty acid

10-14 carbons = medium chain fatty acid

>16 carbons = long chain fatty acid (most common)

How does the number of double bonds affect the created fatty acid?

The number of double bonds determines the firmness(solid or liquid @ room temp), melting point, stability, and oxidation(spoilage) of the fatty acid

What are saturated fatty acids?

Carries max number of H atoms(No double bonds), usually solid at room temp below 10C, much more stable than unsaturated fatty acids

What are unsaturated fatty acids?

Has at least 1 double carbon bond, lower melting point than saturated fatty acids, liquid at room temp, unstable double bonds react with oxygen to form a rancid smell & taste

What are the 2 types of unsaturated fatty acids? Explain each. Provide examples.

Monosaturated - Fatty acid that lacks 2H and has one double bond EX: olive oil

Polysaturated - Fatty acid that lacks 4 or more H and has 2 or more double bonds EX: Vegetable oil

How does the location of the double bonds affect the created fatty acid? What are the 2 systems called? Explain each

Denotes chain length, # of double bonds, & position of double bonds

Delta system - Number starts from carboxyl end of fatty acid

Omega system - Number starts from omega head of fatty acid, takes into account that double bonds are separated by 3C

What are essential fatty acids? What are they required for? Provide an example?

Fatty acids that our body cannot make sufficient amounts of to meet physiological needs

They are required for components of cell membranes and production of eicosanoids

EX: Omega 3 & Omega 6

What do eicosanoids do?

Regulate blood pressure, blood clotting, blood lipid levels, immune responses

What is another name for Linoleic acid? What are some sources of Linoleic acid?

Omega 6

Some sources are: Vegetable oils, meats, nuts, grains

What is another name for Linolenic acid? What are some sources of Linolenic acid?

Omega 3

Some sources are: Soy, leafy veggies, flax seed, nuts, seeds, fish and fish oils

What is a 'cis' configuration?

H atoms are on the same side of the carbon double bond

Lower melting point

Makes the fatty acid go on an angle

Makes a shape like

H

C

C

H

What is a 'trans' configuration?

H atoms on opposite sides of the carbon double bond

Not common in nature

Makes a shape like

H

C

C

H

How are trans configurations of unsaturated fatty acids formed?

Through partial hydrogenation

What is partial hydrogenation?

Bubbles H atoms through unsaturated oil, breaks many carbon double bonds and adds more H atoms, remaining carbon double bonds change into trans fatty acids

What is the purpose of hydrogenation?

Makes more saturated solids, more resistant to oxidation

What are some negative effects of trans fatty acids?

Raises blood cholesterol levels, increases risk of heart disease, lowers good cholesterol and raises bad cholesterol

What is the world health organizations recommended intake level of trans fat?

Under 1% of total energy intake

What are phospholipids?

Is a type of fat/lipid that is found naturally in food. It allows water and oil to mix

What is the purpose of a phosolipid bilayer?

Helps regulate what can pass into/out of the cell

What is a sterol?

-Is a type of fat/lipid that is arranged in rings with various side chains

-Does not dissolve in water

-Plays a role in the production of bile, sex hormones, adrenal hormones, vitamin D, and cholesterol

What is the most common type of sterol role?

The production of cholesterol

What is cholesterol? What is its role?

-Is a type of sterol, which is a fat/lipid

-Only found in animal fats & other animal products

-Not essential

-Plant sterols help reduce cholesterol

Its role is to: produce steroid hormones, vitamin D, Bile, part of myelin, cell membranes, and other important sterols

What are lipoproteins? What are the 4 types?

They are proteins that carry triglycerides, phospholipids, and cholesterol through the blood

The 4 types are: Chylomicrons, very low density lipoproteins (VLDL), Low density lipoproteins (LDL), and High density lipoproteins (HDL)

What kind of cholesterol is good cholesterol? Which is bad?

Low density lipoproteins (LDL) is bad

High density lipoproteins (HDL) is good

Why is Low density lipoproteins (LDL) considered bad cholesterol when compared to High density lipoproteins (HDL)?

LDL is the forward transport of lipids to tissues and carries a majority of cholesterol, causes inflammation

HDL is the reverse transport cholesterol from tissues to liver and plays a role with anti-inflammation

What are the 4 potential fates of lipids?

1. Used as immediate energy

2. Stored in adipose tissue

3. Becomes part of cell membranes

4. Used to produce necessary compounds

How are lipids potential energy sources for the body?

-Oxidation yields ATP+CO2+H20

-Beta-oxidation in the mitochondria

-When fasting or engaging in moderate exercise, the stimulation of fatty acid oxidation occurs to make energy

-After eating, your blood glucose and insulin levels rise, which suppresses fatty acid oxidation and uses less for energy

What is Beta Oxidation process of fatty acids?

1. Fatty acids get transported inside the mitochondria

2. Breaks 16C chain into 2C units

3. Forms 8 molecules of acetyl CoA and 8 high energy electrons to generate ATP

What is ketosis?

-Is the natural response to starvation or a very low carb diet

-Liver converts Acetyl-CoA to ketones, which is then used as energy, excreted in urine, or accumulate in the blood

How are excess lipids stored as adipose tissue?

If there is a sufficient amount of carbs in ones diet to provide energy for the cells, chylomicrons release lipoproteins and VLDL releases lipase, these then enter fat cells to be reassembled and stored through lipogenesis

What are the 11 roles of lipids in the body?

1. Energy source

2. Satiety (Feeling full)

3. Components of all body cells (Phospholipids)

4. Energy reserve (Body fat)

5. Regulate body functions (Flow of molecules in/out cells)

6. Cholesterol used to make several hormones (Sex hormones)

7. Provides essential fatty acids (Omega-3 and Omega-6)

8. Carry fat soluble vitamins (ADEK)

9. Insulation (Subcutaneous fat)

10. Protection (Of organs during trauma)

11. Lubrication (Mucous membranes of eyes)

What happens if there is a deficiency in the essential fatty acids?

Omega-3 - Dermatitis, growth retardation, impaired vision

Omega 6 - Growth retardation, skin lesions, reproductive failure

What happens if you have a low Polyunsaturated fatty acid (PUFA) intake?

Essential fatty acid deficiency during growth

Autoimmune disorders EX: Lupus

Type 2 diabetes

True or false, Dietary cholesterol has a big effect on blood cholesterol?

False, Dietary cholesterol has little effect on blood cholesterol, but a diet with high animal protein intake increases blood cholesterol

Trans fat increases _________ cholesterol and decreases _________ cholesterol.

LDL, HDL

Some saturated fats are hypercolesterlemic. What does this mean?

It increases LDL cholesterol and HDL cholesterol

Why is there no AI, RDA, or UL for total fat intake?

Insufficient data to determine what level of fat intake can prevent/reduce the risk of chronic diseases or cause adverse effects

Why should you not restrict infants and small childrens fat intake?

Severe fat restrictions risk essential fatty acid deficiencies, impaired growth, greater risk of chronic disease

Why is there no DRI for saturated fat and trans fat?

Saturated Fat: It's impossible to isolate saturated fat in a diet. It's safer to limit saturated fat consumption

Trans Fat: Not an essential fat because our body makes enough naturally and we do not need extra from our diet

What is the DRI and UL for cholseterol?

There is no DRI or UL for cholesterol

How can you lower your fat intake?

Eat plenty of fruits, vegetables, and grains

Reduce fat intake

Consume low fat dairy products

Choose lean meat

What are proteins? What are the 2 types/

Chains of amino acids in different sequences

Dipeptide and Polypeptide

How are proteins similar to Carbs and Fats?

Proteins are found in a variety of foods and the human body is able to make them to a certain degree

How are proteins different to Carbs and Fats?

Proteins are made according to instructions from DNA

Proteins contains Nitrogen from the amino acids

How many amino acids are there? How many are essential? How many are non-essential?

There are 20 different amino acids. 9 of which are essential and 11 are non-essential and conditionally essential

What makes an amino acid essential?

They cannot be made by the body and need to be consumed through regular diet

What makes an amino acid non-essential or conditionally essential?

Non-essential amino acids can be produced by the body through transamination

Conditionally essential amino acids are made in the body, but not at a high enough rate to meet body's needs

What are the 3 characterstics of amino acids? What is the job of all 3?

Number

Proportion

Order

These characteristics fold the amino acid into a specific orientation, giving each protein a unique 3D shape that is essential for the proteins function. Can created 10,000-50,000 unique proteins

How is a peptide bond formed?

The amine group of one amino acid binds to the acid group of another amino acids

How does structure determine a proteins function?

Dipeptide: 2 amino acid resdiues

Tripeptide: 3 amino acid residues

Oligopeptide: 4-9 amino acid residues

Polypeptide: 10+ amino acid residues

What are the 4 steps of a protein structure? Explain each

Primary- Linear sequence of amino acids

Secondary- 3D elements

Tertiary- Further folding

Quanternary- Bonds between 2 or more polypeptides interact, creating a functional protein EX: Actin

What are 2 changes to protein structure? Explain each.

Denaturation - caused by: Changes in pH, Temperature, UV rays, etc. The alteration of 3D structure EX: Egg whites turning white during cooking process

Mutation - Alterations in base sequence of genes that codes for specific proteins, which then changes their function EX: Sickle shaped red blood cell

What are the 7 functions of proteins?

1. Tissue maintenance & growth

2. Formation of essential compounds

3. Nutrient transport

4. Water balance

5. Buffering

6. Defense & detox

7. Source of energy & glucose

What is protein turnover?

Body proteins are continually degraded & replaced but the total amount of body protein is relatively stable

What does new muscular growth depend on in terms of nutrition?

Depends on availability of amino acids in excess of maintenance needs

What is collagen?

Protein framework for bones, teeth, etc

Protein is required for the production of?

Enzymes, Hormones, Carriers, Blood clotting compounds, etc

Most transporters are ___________?

Protein EX: lipoprotein carries TG, Cholesterol, phospholipids

What happens when there is a deficency of transport proteins?

Reduces absorption and/or transport and availability of the compounds it carries

How do proteins help with water balance?

Intercellular/interstitial fluid balance is controlled by proteins levels and ions

What can potentially cause low blood protein?

Chronic low protein intake

Excess loss of protein

Inadequate protein synthesis

What is a buffer? How do proteins effect this?

A compound that maintains pH by resisting changes due to the presence of aids or bases

Proteins have a negative charge on their surface that attracts H+ ions

How does protein affect the defense and detox of the body?

Antibodies are protein. Each antibody binds a specific antigen and plays a role in the elimination of that antigen

Inadequate protein intake = Compromised immune response = lower resistance to infection and lower detox capabilities

How is protein used as a source of energy and glucose?

Protein can be sacrificed to produce energy and glucose in the absence of adequate fat and carbs

How are food alergies triggered?

When a protein from the diet is absorbed without being completely digested

What is an amino acid pool?

All amino acids in body tissues and fluids available for use

Protein metabolism involves what 4 categories? How are they interrelated?

Protein synthesis

Synthesis of other nitrogen compounds

Deanimation (Degradation)

Energy production

The decrease in 1 leads to increase in another

How is protein synthesis part of protein metabolism?

Mostly anabolic hormones (Insulin, androgen, growth hormone) which increases the rate of protein creation and Catabolic hormones (Thyroid, adrenocortical hormones) which decreases the rate of protein creation

How is the synthesis of other N compounds part of protein metabolism?

Nitrogen from amino acids are removed and can be used to form non-protein nitrogen containing compounds EX: DNA nucleotides

When does degradation occur in protein metabolism?

1. During protein turnover

2. When dietary protein exceeds maintenance and growth needs

3. Low energy intake, sacrifices protein for fuel

How is urea formed and excreted?

Formed: Body removes an amino group from amino acids, produces ammonia, ammonia converted to urea, urea filtered by kidneys,

Excreted: kidneys need water to get rid of urea, more urea produced, requires more water, in water intake doesn't occur then water is taken from the body, excess urea changes pH level

How is energy production of protein metabolism?

Protein gets broken down into ATP through the mitochondria

How does nitrogen balance influence protein synthesis and protein breakdown?

Measures nitrogen intake from dietary protein

+Nitrogen balance = Protein synthesis

-Nitrogen balance = Protein breakdown

How does a negative nitrogen balance happen? Positive balance?

Negative nitrogen balance: Dietary nitrogen intake < nitrogen loss/excretion. EX:Severe energy deficiency, immobility, stress, injury, overtraining

Positive nitrogen balance: Dietary nitrogen intake > nitrogen loss/excretion. EX: Infancy, childhood, prego, recovering from illness

What are the 2 categories of protein quality?

Amino acid composition and digestibility of protein

How does amino acid composition play a role in protein quality?

Amino acid composition is determined by the type and proportion of amino acids present in a food protein

What are the 2 types of proteins? Explain each

Complete protein - Dietary protein containing all 9 essential amino acids in amounts adequate for human use EX: Animal proteins

Incomplete protein - Lacks or contains limited amounts of one or more essential amino acids, could not support growth is sole source of protein

Why must protein digestibility be accounted for?

The amount of amino acids in a food doesn't determine the quality of the protein, its how much amino acids are absorbed

What are complemenatary proteins?

2 or more proteins whose amino acid profiles complement each other in a way that essential amino acids missing from one protein is supplied by the other EX: Steak + Broccoli

What is the difference between animal proteins and plant proteins?

Animal products: provide sources of protein, B vitamins and minerals such as iron, zinc, and calcium. But are low in fibre and can be high in fat

Plant products: Provide sources of protein, B vitamins, iron, zinc, fibre and calcium. But in less absorbable forms

What are the dietary requirements for protein?

10-35% of our total daily energy

Mixed protein quality

0.36g / lb body weight or 0.8g / kg body weight

How are vitamins different to macronutrients?

Daily vitamin needs are small

Not a source of energy

Individual units

How are vitamins simialr to macronutrients?

Both contain carbon

What are fat soluble vitamins?

Vitamins A, D, E, K

Intestinal cells absorb fat soluble vitamins and package them into lipoproteins -> Released to lymph system -> goes through liver -> Stored/re-packaged for delivery to other tissues

Excess is stored in liver and fatty tissues

What are water soluble vitamins?

B Vitamins and Vitamin C

Get abosrbed right into blood stream

Not stored

Excess excreted in urine

Fragile compared to fat soluble vitamins

More processing = Greater or less loss in vitamins?

Greater loss in vitamins

How many B vitamins are there? What are some examples?

8

Thiamin(B1)

Riboflavin(B2)

Niacin(B3)

Biotin

Pantothenic acid

Vitamin B6

Folate

Vitamin B12

What is vitamin C?

An antioxidant

Works with fat soluble antioxidant Vitamin E

What are the B vitamins? What is the analogy to help understand this concept?

Act primarily in energy metabolism as coenzymes

Analogy: Your car keys are the coenzyme, your car is the enzyme, you driving to your destination is the reaction taking place in your body