Physiology Wk 10 - metabolism and nutrition

What are nutrients in the body used for?

promote normal growth, maintenance, or repair

What do major nutrients include?

proteins, carbohydrates and lipids

What do minor nutrients include?

vitamins and minerals

Where do most carbohydrates (sugar and starch) come from?

plants; exceptions include milk sugar and small amounts of glycogen in meats

What are lipids in diet?

usually triglycerides, or neutral fats

Where do saturated fats come from?

animal products

Where do unsaturated fats come from?

plants

Where do proteins come from?

eggs, meat, fish, meat products and combinations of grains and vegetables that provide all 8 essential amino acids

What do vitamins act as?

coenzymes

What are minerals?

inorganic nutrients required by the body, includes: calcium, phosphorus, potassium, sulphur, sodium, chloride and magnesium

What is metabolism?

all chemical reactions in the body. energy released as bonds are broken is harnessed to make it ATP. includes catabolism and anabolism

What is catabolism?

breakdown of substances into smaller, simpler ones

What is anabolism?

the buildup of substances into larger, more complex ones

What is the major fuel for making ATP in most body cells?

glucose, or blood sugar

How does glucose make ATP?

it’s “squeezed” in a series of reactions to release energy that will be used to make ATP. any carbon released leaves as carbon dioxide. hydrogens released will eventually help form water when combined with oxygen

What does cellular respiration involve?

- glycolysis (breaks glucose down to pyruvate)

- citric acid cycle

- the electron transport chain

What is the most concentrated form of stored energy in the body?

fats, they are used to make or repair cell membranes, myelin sheaths and fatty cushions around some organs

What are proteins used for?

to make both functional and structural proteins. they are used to make ATP only when in excess or when sugars and fats are not available, e.g. starvation

What does the liver do in metabolism?

digestion, detoxifies drugs and alcohol, degrades hormones and produces essential product such as clotting proteins and albumin. liver cells make nonessential amino acids and detoxify ammonia by combining it with carbon dioxide into urea

What happens after absorption?

all nutrients are taken to eh liver first through the hepatic portal circulation. liver cells take what they need and remove harmful bacteria before nutrients enter the general circulation

How does the liver help maintain blood glucose homeostasis?

by storing glycogen, by releasing glucose from glycogen through the process of glycogenolysis, or by making additional glucose as needed through gluconeogenesis

What does cholesterol make?

NEVER to make ATP. its used to make cell membranes, vitamin D and steroid hormones

What is energy intake?

the energy released during food oxidation and equals total energy output

What is Basal Metabolic Rate (BMR)?

the amount of energy the body uses at raced to carry out essential life activities

What is BMR influenced by?

age, gender and body surface area

What is Total Metabolic Rate (TMR)?

total number of kilocalories the body must consume to fuel all activities

How is heat lost from the body?

through radiation and evaporation