BIO100 Nutrition Reading #3

Protein

The most diverse large biological molecule that plays many important roles in the body.

- made from joining many amino acid monomers together

- shape and order determine function

Functions of Proteins

- Structure (ex: keratin in nails)

- Transport (hemoglobin transporting oxygen in body)

- Defense (antibodies)

- Enzymes (lactase)

- Movement (Actin allows muscles to contract)

STEMD

How does one amino acid change in a sequence effect a protein?

It could alter its shape and function. For example, sickle-cell disease stems from the mutated shape of hemoglobin.

Core Question:

What is a polypeptide? What does the name mean?

A polypeptide is a chain of amino acids joined by many (or "poly") peptide bonds.

Anatomy

The study of the structure of an organism's body parts/forms

Physiology

The study of the function of an organism's body parts.

Core Question:

Your brain is an example of what level of the structural hierarchy?

An organ.

What is the structural hierarchy in animals?

1. Cell

2. Tissue

3. Organ

4. Organ System

5. Organism

Tissue

An integrated group of similar cells that together form a function.

Homeostasis

A tendency in animal bodies to maintain relatively constant internal conditions even when external environmental changes occur.

Homeostasis in Diabetes

The body of a person either fails to produce insulin (type 1) or target cells do not respond normally to insulin produced (type 2, obesity). Without the regulation of insulin, the cells cannot contain enough glucose from the blood.

Integumentary System

Organs such as skin, hair, and nails that protect the body against physical harm.

Homeostasis

- produce heat by shivering

- layer of fat for insulation

- blood vessels that widen or narrow to regulate heat loss

Negative Feedback

The form of regulation in which the result of a process inhibits that very process.

- ex: a thermostat

Core Question:

Flushing a toilet causes water to rush into the tank, which lifts a float until it turns off the water. Explain how this demonstrates negative feedback.

This is an example of negative feedback because the result of the process (water entering the tank) turns off that process.

What are the two broad categories of ailments with the digestive system?

Malfunctioning/diseased digestive organ or improper diet (nutritional imbalance)

Examples of malfunctioning or infected digestive organs

- Acid reflux (backflow ofof partially digested food

- Gallstones (solid crystals that obstruct the gallbladder)

- Constipation (slow movement of feces in the colon)

- Appendicitis (infection of appendix by bacteria)

- Ulcer (damage of mucus lining in the stomach)

- Cholera (improper sanitation infection)

- Inflammatory Bowel Disease

Gastric Bypass

A common weight loss surgery where the size of the stomach is reduced in size. A portion of the small intestine downstream is attached to bypass the large portion of the stomach. Patients quickly feel full because of the reduced size and shorter intestine.

Nutritional Imbalances

Severe health consequences caused by an improper diet

- obesity

- malnutrition

- eating disorders

Obesity

An inappropriately high body mass index (BMI). The largest concern of nutritional imbalance.

- can lead to type 2 diabetes

- 15 kinds of cancer

- cardiovascular disease

Body Mass Index (BMI)

A ratio of weight to height used the main indicator of obesity, overweight, etc.

Malnutrition

A diet that lacks the sufficient calories or essential nutrients.

- caused by inadequate intake or medical problems

- most common form is protein deficiency (not enough amino acids)

- vegans/vegetarians, underresourced nations

Anorexia Nervosa

An eating disorder caused by self-starvation due to a fear of gaining weight, even when one is underweight.

Bulimia

An eating disorder characterized by a pattern of binge eating followed by purging through induced committing, misuse of laxatives, or excessive exercise.

Core Question:

Is it possible for someone to be both obese and malnourished?

Yes, if someone eats too many calories but not enough nutrients.

Osmoregulation

The control of the gain or loss of water and dissolved ions.

Urinary System

Balances the amount of water in the body by excreting waste-carrying urine while keeping the proper amounts of water and the important substances.

- kidneys are the central hub

- reclaims water and vital substances and returns them to circulation

Dialysis

The filtration of the blood by a machine that acts as an artificial kidney.

- costly

- time consuming

- alternative to a kidney transplant (wait time)

Kidney

The main organ of the urinary system that filers blood for toxic waste and places them in the tubules which lets needed substance to go back to the bloodstream.

Nephron

In a kidney, consisting of one tubule and surrounding capillaries where the blood is filtered and urine is formed.

- millions in each kidney

Core Question:

What is the functional unit of the urinary system, where urine is actually formed?

The nephron.