Proteins and Lipids

Collagen

Example of protein — Structural

Hemoglobin

Example of protein — Transport and binding

Amylase

Example of protein — Enzymatic

Hormones

Example of protein — Regulation

Immunoglobulin

Example of protein — Protection

Amino acid

Each protein is made up of _____

C, H, O, N

Each amino acid is built on a similar overall plan containing the same four elements: _____

L form

Structural form of protein most commonly found in organisms

Essential (Non-dispensable)

Amino acids that cannot be synthesized by the body and must be obtained from the diet

Non-essential (Dispensable)

Amino acids that can be synthesized by the body and are not required to be part of the diet

9

There are how many essential amino acids?

water; peptide bond

When 2 amino acids are joined, _____ is eliminated and a _____ is formed; this is known as dipeptide

Fibrous (elongated) or Globular (rounded)

Produced proteins are either _____ or _____

Myoglobin or hemoglobin

Contain iron-containing heme groups; heme proteins

Salivary proteins

• contain sugar and sugar acids such as sialic acid

• make saliva bind better with water

Sialic acid

Salivary proteins contain sugar acids such as _____

Bolus

Moistening the food creates a _____

Parietal cells

HCl in the stomach is produced by _____

HCl

It denatures the protein in the stomach

Chief cells

Cells in the stomach that secrete pepsinogen

Pepsin

The acidic environment (stomach) converts pepsinogen into active protease _____

Pepsin

Protein cleaving enzyme

Small intestine

Further breakdown of proteins occurs in the _____

Hepatic portal system

Amino acids from protein digestion are transported to the liver via the _____ before being distributed to the body

Liver

Site of amino acid synthesis

0.8g/kg

For healthy adults, the RDA for protein is _____

15%

Approx. how much of total calories are obtained from proteins?

7g

A single ounce of meat provides ___g of protein

2g

How many g of protein per serving of vegetables?

8g

How many g of protein per glass of milk?

Calcium

High protein uptake decreases _____ levels

Anticoagulant

What is warfarin activity?

Low

High protein = _____ warfarin

Protein-energy malnutrition (PEM)

Inadequate caloric and protein intake may lead to a severe condition known as _____

Marasmus

• Chronic form of Protein-Energy Malnutrition (PEM)

• often seen in children with insufficient food

• common in children 6-18 months

• may not have been receiving mother’s milk

• malnutrition leads to muscle weakening, impairment of brain, and nervous development

• children with this are often seen to be old and shirveled

Kwashiorkor

Acute form of Protein-Energy Malnutrition (PEM)

• from a sudden and recent food deprivation

• common in children 18-24 months

• develops when a child is weaned to a low nutrient diet from the complete nutrition provided by mother’s milk

• may also develop from infection/weakened condition that alters nutritional needs

• skin is scaly, patchy, sores develop and may not heal

Kwashiorkor

Ghanian term — weaning of the 1st child at the time the 2nd child is born

Edema

In Kwashiorkor, this develops in the abdomen and the face

Tyrosine

Which amino acid is lacking in Kwashiorkor that leads to the pigment melanin not being made?

Dysentery

Fluid imbalance (Kwashiorkor) may trigger _____

Kwashiorkor

• lack of irons leads to unbound iron promoting bacterial growth

• hemoglobin and other blood proteins are not synthesized; anemia and weakening

• immune system is suppressed

• Immunoglobulins are cleaved to become amino acids needed by the body

Marasmus

The body’s adaptation to starvation

Kwashiorkor

The condition arising from a failure to meet the body’s demands

Lipids

• A compound that is soluble in an organic solvent

• Insoluble in water (hydrophobic)

• Functions:

  • provide calories

  • source of essential fatty acids

  • structural component of cell membrane

Lipids

Delays emptying of food, stimulates the release of leptin

Leptin

Lipids stimulate the release of _____, which regulates satiety

• Triglycerides

• Sterol

• Phospholipids

Relevant lipids in food and nutrition

Macronutrient

Dietary fat is classified as a _____

Fats

The most calorically dense macronutrient

9 kcal per gram

How many kcal per gram of fat

Nuts, seeds, olives, avocados

High in unsaturated fat

Lingual lipase

Digestion starts in the mouth via a _____, which helps digest lipids

Gastric lipase

An enzyme secreted by the chief cells of the stomach that helps digest fats

Cholescystokinin (CCK)

Stimulates the gallbladder and pancreas to release bile

• enzyme for fat metabolism

Fatty acids, bile salts, monoglycerides

Final products of lipid digestion

Very low density lipoproteins (VLDL)

• transports all triglycerides from liver to muscle and adipose tissue

• packed into VLDL for export into the blood

• primary transport system of endogenous lipids

Low density lipoprotein (LDL)

• transport cholesterol from liver to body tissues

• liver synthesizes enough cholesterol from the diet; this causes the liver to reduce cholesterol synthesis for balance

Bile acids

Cholesterol can only be excreted from the body via _____

High density lipoproteins (HDL)

• Contains high amounts of protein compared to other lipoproteins

• helps remove excessive cholesterol from tissues back to the liver for excretion or recycle

High serum LDL-c

Associated with increased formation of fatty plaque on artery walls

HDL-c

Can protect against atherosclerosis

• Subcutaneous adipose tissue

• Intraperitoneal or visceral adipose tissue

• Muscle

Lipids can be stored in _____

Omega 3 polyunsaturated fatty acids

Useful in managing periodontal disease due to its anti-inflammatory and abc properties

Cholesterol

Triglycerides are packaged with _____

Chylomicrons

Phospholipids are processed with _____

Triglycerides

If the body is at rest, fatty acids are taken up by adipose tissue for storage as _____

oxidized

If the body is active, fatty acids will be _____ to provide ATP

Small intestine or liver

Classes of lipoproteins are also assembled in the _____

Density

Lipoproteins are classified according to their _____

Triglycerides

VLDLs get smaller and denser, becoming LDL when they lose _____

Obesity

Most common outcome of excess caloric intake

Metalloproteins

Zinc-binding protein that is associated with a taste bud; gustin

Proteolysis

Yields smaller lengths of polypeptides and some amino acids