Unit 5: A&P - Nutrition and Metabolism

Define this:
Study of how living organisms obtain and utilize nutrients needed to grow and
sustain life

Nutrition

Define this categories of nutrients:
Carbohydrates, lipids, proteins
Must be consumed in relatively large quantities, needed in daily amounts

Provide fuel for cellular respiration to form ATP

Macronutrients

Define this categories of nutrients:

Vitamins and minerals
Must be consumed in relatively small quantities

Micronutrients

Define this categories of nutrients:

Must be obtain and absorbed via digestive system from die

Essential

Define this categories of nutrients:

Provided by biochemical processes of body, not required in diet

Vital to life and liver can usually convert another nutrient into one needed

Nonessential

Define this:

Amount of each nutrient that must be obtained each day, established values for
nutrients set by federal agencies

Recommended daily allowance

Which one of these is not used for glucose in the body?

Immediate use for fatty acid oxidation (burning fats)

What is most abundant form of lipids?

Triglycerides

Where is saturated fats found?

Meat, diary food, tropical oils, or hydrogenated oils

Where is unsaturated fats found?

Seeds, nuts, olive oil, and most vegetable oils

Where is polyunsaturated fats?

Corn Oil and soybean oil

Define this lipid:

Required as components of plasma membrane

Precursor hormone for steroid hormone, bile salts, and Vitamin D

Comes from diet or metabolic pathways in liver

Cholesterol

What is not a function of cholesterol?

Acting as a carbohydrate for cellular respiration

What is not a source of protein?

Glucose

Proteins provides a source of what needed gas?

Nitrogen

During growth, pregnancy, recovering from injury, we absorb more nitrogen than excreted showing?

Positive nitrogen balance

During blood loss, malnutrition, can be fatal, where more nitrogen excreted than absorbed?

Negative nitrogen balance

What are the water-soluble vitamins?

B complex, C, B12

What are the fat-soluble vitamins?

A, D, E, and K

What are the seven major minerals?

Ca, P, K, S, Cl, Mg, Na

What minerals are needed in TRACE amounts?

Cr, Cu, I, Fe, Z

What helps to balance toxic overload during minerals?

Uptake and excretion

Which one of these is not a use of mineral in the body?

Minerals make up bones and teeth

What is metabolism?

Sum of all biochemical reactions in the body

Define this reaction:

Builds molecules (small → large)

Anabolism

Define this reaction:

Breaks molecules down (large → small)

Cellular Respiration

Glycolysis

Catabolism

What is the fed (absorptive) state?

Period after eating when nutrients are absorbed and stored

Main hormone in absorptive state?

Insulin

What triggers insulin release?

High blood glucose + amino acids + GIP + parasympathetic stimulation

Which of these is not a MAIN effect of insulin?

Stimulates glycogen breakdown (glycogenolysis)

What does insulin inhibit?

Gluconeogenesis + glucose release from liver

What is the postabsorptive state?

Between meals when body uses stored energy

Main goal of postabsorptive state?

Maintain blood glucose (glucose sparing)

Main hormone in postabsorptive state?

Glucagon

What is not a function of glucagon?

Promotes glucose uptake into cells

What is glucose sparing?

Using fats instead of glucose so brain gets priority fuel

(True/ False) Cholesterol used for energy.

False

What are lipoproteins?

Protein-lipid transport particles in blood

Define this type of cholesterol:

Removes cholesterol from blood → liver

High protein content

Considered good

HDL

Define this type of cholesterol:

Delivers cholesterol to tissues → can build up in arteries

Highest cholesterol count

LDL

Define this type of cholesterol:

Transports triglycerides from liver → fat storage

VLDL

Define this type of cholesterol:

Carry dietary fats from intestines

Almost entirely of triglycerides

Chylomicrons

What do statin drugs do?

Inhibits for HMG-CoA (enzyme needed for cholesterol synthesis)

What are the quick three stages in processing nutrients?

1. Digestion & Absorption

2. Synthesis of lipids, proteins, glycogen

3. Catabolism (convert glucose into pyruvic acid and acetyl-CoA)

4. Oxidative breakdown of intermediates into CO2, water, and ATP (in mitochondria)

What keeps intracellular glucose low?

Conversion of glucose to glucose-Six-phosphate and it becomes trapped into certain cells

What cells can reverse glucose-Six-phosphate?

Intestine, kidney, and liver

Define this carbohydrate metabolism:

Too much glucose and high levels of ATP available

Converts glucose to glycogen for storage (liver)

Glycogenesis

Define this carbohydrate metabolism:

Not enough glucose available

Glycogen stored in the liver and muscle cells of animals broken down into glucose

Maintains blood glucose levels during fasting

Glycogenolysis

Define this carbohydrate metabolism:

Creates glucose from other molecules

Occurs mainly in liver

Gluconeogenesis

What transport fat digestion in lymph?

chylomicrons

Define this:

Occurs in mitochondria

Breaks down 2-carbons at a time

Forms acetyl-CoA which enters citric acid cycle

Beta-Oxidation

Define this lipid metabolism:

Triglyceride synthesis that occurs when cellular ATP and glucose levels are high

Lipogenesis

Define this lipid metabolism:

Breakdown of stored fats into glycerol and fatty acids; reverse of lipogenesis
Fatty acids are actually preferred by liver, cardiac muscle, resting skeletal muscle
Accelerated when carbohydrate intake is inadequate

Lipolysis

Define this homeostatic imbalance;

Accumulation of ketone bodies

Common in starvation, unwise dieting

Ketosis

Define this homeostatic imbalance:

Ketones are acidic, so a buildup of these molecules

Patients breath can smell fruity from vaporizing acetone

Metabolic acidosis

Define this:

Removed NH2 then converted into pyruvic acid or one of the keto acids

Deamination

Define this:

Changing of one nutrient biomolecule into another

Ex; Glucose broken down to acetyl CoA
Then synthesized into triglycerides and stored
Instead of entering citric acid cycle

Nutrient Interconversion

Define this:

If energy intake equals energy output, then a person’s weight is stable = energy balance

Basal Metabolic Rate

Define this:

A formula used to determine obesity based on a person’s weight relative to height

Reflect energy body needs to perform its most essential activities

Measured in post-absorptive state

Body Mass Index (BMI)

What affects the BMR?

• Age and gender (decreases with age)

• Body temperature (increases with temperature)

• Thyroxine (increases oxygen consumption, cellular respiration, BMR)

What affects the TMR (BMR + metabolism)?

1. Amount of skeletal muscle and its activity

2. Food Intake

3. Changing environmental conditions (increases TMR)

What determines body temperature?

Balance between heat production and heat loss

Normal body temperature?

~98.6°F (37°C)

Why is high body temperature dangerous?

Denatures proteins and depresses neurons

Life-threatening temperature limit?

~109°F

Main thermoregulatory center?

Preoptic region of hypothalamus

What inputs does hypothalamus receive?

Skin (peripheral thermoreceptors)

Core body (central thermoreceptors)

What happens during vasoconstriction in cold?

Reduces heat loss from skin

What is shivering?

Skeletal muscle contractions that generate heat

What is nonshivering thermogenesis?

Heat production via epinephrine/norepinephrine (especially in infants)

What tissue is important for nonshivering thermogenesis?

Brown adipose tissue

Which organs produce most heat at rest?

Liver, brain, heart, kidneys, endocrine organs

What increases heat production during exercise?

Skeletal muscle activity

Most important hormone for temperature regulation?

Thyroid hormone

What does thyroid hormone do?

Increases metabolic rate → raises body temperature

What happens when body temperature drops?

Hypothalamus releases TRH → anterior pituitary releases TSH → thyroid releases thyroid hormone