Human Nutrition

Question 1

What is your appetite control center called?

Answer 1

Hypothalamus which responds to hormones/ nerve signals

Question 2

What is Ascorbic Acid?

Answer 2

Vitamin C

Question 3

What is the criteria for an essential nutrient?

Answer 3

cannot by synthesized by the body, must be included in the diet

Question 4

What is the criteria for a non-essential nutrient?

Answer 4

can be synthesized by the body or have a replacement nutrient that serves the same purpose, not necessary in the diet

Question 5

What are the consequences of protein deficiency malnutrition?

Answer 5

-Muscle loss for energy
-Lack of menstrual cycle
-Lack of blood plasma proteins
-physical/ mental development retarded

Question 6

What are the constants in a calorimetry experiment?

Answer 6

-Mass of food
-Volume of water
-Distance between food source and calorimeter
-starting temperature of the water

Question 7

What could be source of error in a calorimetry experiment?

Answer 7

Food sample did not fully combust, heat loss into the environment

Question 8

What are the causes of Vitamin D deficiency?

Answer 8

-Not enough dietary sources (fish oils, egg yolk, enriched dairy products)
-Not enough exposure to UV light for body to synthesize

Question 9

What is a similarity between vitamins and minerals?

Answer 9

-Both are required in small quantities
-Both are obtained in the diet

Question 10

What are the differences between vitamins and minerals?

Answer 10

-Vitamins are organic, carbon-based compounds while minerals are inorganic ions

Question 11

What tissue is broken down first with malnutrition and why?

Answer 11

Adipose Tissue (fat) because it is high in nutrients

Question 12

Anorexia nervosa is caused by…

Answer 12

improper intake of nutrients (too little = undernutrition) which can be caused by social/ socioeconomic factors

Question 13

What are the consequences of Anorexia Nervosa?

Answer 13

-Body will begin to break down its OWN tissue as not receiving enough energy from diet (adipose (fat) tissue broken down first as fats contain more energy and their breakdown does not (usually) disrupt homeostasis)
-After adipose tissue broken down, muscle tissue broken down to provide proteins
-IF enough bodily tissue is broken down, organs can become severely damaged and this can lead to death.
-In severe cases, body breaks down heart
muscle (which can lead to death).
-As heart muscle atrophies and weakens, blood flow is reduced and blood pressure drops.
-Heart may also develop arrhythmias
(irregular rhythms/ beats) due to electrolyte imbalances.

Question 14

What are some causes of malnutrition?

Answer 14

-Deficiency in an essential nutrient
-Excess of a nutrient
-May be to social factors
-improper use of nutrients due to a malfunction of the hypothalamus

Question 15

What are the consequences of malnutrition?

Answer 15

-can lead to break down of body tissues
-anorexia can lead to organ failure
-obesity can lead to problems like diabetes and coronary heart disease

Question 16

What is hypertension?

Answer 16

high blood pressure

Question 17

A person has hypertension when their heart rate is over…

Answer 17

120/80

Question 18

Why is vitamin D unique?

Answer 18

can be synthesized by humans via skin

Question 19

What are the causes and consequences of Phenylketonuria (PKU)?

Answer 19

-genetically inherited disease (autosomal recessive) caused by a person’s chemical inability to metabolize the aa phenylalanine (into tyrosine)
-(Phenylalanine builds up in tissues & bloodstream due to lack of enzyme (phenylalanine hydroxylase) that breaks phenylalanine down into tyrosine, from inheriting mutated form of gene
-Most common in European populations and less common in Asian, Latino, and African populations
-Excess phenylalanine may result in mental deficiency, behavioral problems, seizures & other developmental problems)

Question 20

What are the treatments of PKU?

Answer 20

-Low-protein diet that limits intake of protein sources that contain phenylalanine
-Supplemented with a formula containing essential amino acids/ tyrosine

Question 21

What is the definition of malnutrition?

Answer 21

a health condition caused by deficiency, imbalance, or excess nutrients in the diet

Question 22

What are the consequences of Vitamin D deficiency?

Answer 22

lack of vitamin D leads to lowered Ca2+, which causes rickets in children (growth plates do not mineralize/ thick bones/ decreased height/ bowed legs); causes osteomalacia in adults (soft/ weak bones)

Question 23

Appetite: Inhibitory (promote fasting = do not eat)

Answer 23

-Vagus nerve sends nerve signals to hypothalamus when stomach stretches/ distends = full
-Insulin from pancreas (high blood sugar)
-CCK from intestines (as chyme moves into intestine from stomach)
-Leptin from adipose (fat) tissue (more fat = more leptin = less eating)

Question 24

Appetite: Stimulatory (promote feasting = eat)

Answer 24

-Glucagon from pancreas (low blood sugar)
-Ghrelin from stomach (empty = feed me)

Question 25

What is a cause of protein deficiency?

Answer 25

a lack of 1 or more essential amino acids, so that certain proteins cannot be synthesized

Question 26

Explain how to determine the energy content of food.

Answer 26

-By combusting (burning) a known mass of a food sample, the energy content of the food can be calculated by measuring the heat energy released from the burning food using a CALORIMETER (a vessel filled with a known quantity of water at a known temperature).
-Heat from the burning food is transferred to the water and the temperature increase of the water is used to calculate the energy content of the food sample (using the specific heat capacity of water: the amount of energy required to raise 1g of water 1℃ = 4.18 Joules)
-Energy Content of Food (Joules) = Mass of water (g) x 4.2 (J/g℃) x Temp increase (℃)

Question 27

What are the conditions that must be kept consistent in calorimetry?

Answer 27

Mass of food sample
Mass/ volume of water (1g = 1ml)
Starting temperature of water
Distance between calorimeter and burning food sample

Question 28

Functions of Vitamin D

Answer 28

aids in bone formation/ repair, and aids in bone mineralization (aids in Ca2+/ phosphorus absorption which help bones mineralize

Question 29

Unsaturated Fatty Acids (Essential Nutrients)

Answer 29

Omega 3 and 6

Question 30

What are the functions of Minerals

Answer 30

used in long-term structures/ molecules (Ca2+ in bones/ Fe3+ in hemoglobin) and function as electrolytes (Na+ and Ca2+ in muscle contraction; Na+, K+, Ca2+, and Cl- in action potentials/ synaptic transmission)

Question 31

Another example of an essential nutrient

Answer 31

water

Question 32

Appetite Definition

Answer 32

desire to eat

Question 33

BMI=

Answer 33

mass (kg)/ height (m)

Question 34

Overweight/ obese individuals Overview

Answer 34

overnutrition (larger portions, overeating, insensitivity to leptin) and decreased energy expenditure/ physical activity = higher BMI (body mass index)

Question 35

Type II Diabetes (Obese Individuals are More Likely to Suffer from)

Answer 35

(excessive overstimulation of cells by insulin due to overeating/ eating larger portions of sugar-rich foods leads to insulin insensitivity/ cells become desensitized to insulin and blood sugar remains high = hyperglycemia)

Question 36

Hypertension = high blood pressure (Obese individuals are more likely to suffer from)

Answer 36

(consistently greater than 120/80 mmHg); more weight = faster heart rate to move blood; can be due to higher cholesterol/ plaque deposits in arteries (narrows arterial lumen/ decreases arterial diameter/ hardens arteries/ decreases arterial elasticity = atherosclerosis); high cholesterol is an indicator of CHD (coronary heart disease) and hypertension is often a precursor to CHD

Question 37

Fats/ cholesterol are….

Answer 37

non-polar, so transported in blood as lipoproteins. (2 types)

Question 38

Low Density Lipoproteins (LDL)

Answer 38

transport cholesterol from liver to body (↑ blood cholesterol)

Question 39

High Density Lipoproteins (HDL)

Answer 39

transport cholesterol from body to liver (↓ blood cholesterol)

Question 40

Saturated fats (impact on blood cholesterol levels)

Answer 40

↑LDL levels = ↑BLOOD CHOLESTEROL

Question 41

Trans Fats (impact on blood cholesterol levels)

Answer 41

↑LDL levels and ↓HDL levels = SIGNIFICANTLY ↑BLOOD CHOLESTEROL

Question 42

Cis-polyunsaturated fats (impact on blood cholesterol levels)

Answer 42

↑HDL levels = ↓BLOOD CHOLESTEROL levels

Question 43

Coronary Arteries

Answer 43

-supply oxygenated blood directly to the heart itself.
-IF there are high levels of LDL in the bloodstream, LDL particles form deposits in artery walls (including coronary arteries).
-Coronary heart disease (CHD) is the development of atherosclerosis in the coronary arteries, which can lead to heart attack and stroke.

Question 44

Starvation

Answer 44

severe restriction (deficiency) of energy/ nutrient intake; can lead to body breaking down OWN tissues for energy (fats = first because more energy/ do not disrupt osmotic balance/ homeostasis; muscles after fats to provide protein); if enough body tissue broken down = severe organ damage/ death

Question 45

Carbohydrates Energy

Answer 45

“quick energy”/ easier to digest and transport so body’s preferred energy source

Question 46

Lipids Energy

Answer 46

store ~2x energy as other molecules but difficult to digest and transport so used for long-term energy storage in adipose tissue

Question 47

Proteins Energy

Answer 47

aa’s used to build muscle tissue and can be used in cellular respiration but metabolism more difficult as breakdown produces nitrogenous waste = urea in humans (removed by kidney)