MBS 217 Lecture 11

Question 1

Define nutrient

Answer 1

a substance in food that promotes normal growth, maintenance, and repair

Question 2

Major nutrients

Answer 2

Carbohydrates, lipids, and proteins

Question 3

Food equals energy

Answer 3

ATP

Question 4

Energy can be derived from

Answer 4

Protein
Carbohydrates
Fats

Question 5

Types of carbs

Answer 5

Starch (complex carbohydrates) in grains and vegetables

Sugars in fruits, sugarcane, sugar beets, honey and milk

Insoluble fiber: cellulose in vegetables; provides roughage

Soluble fiber: pectin in apples and citrus fruits; reduces blood cholesterol levels

Question 6

Glucose is the fuel used by cells to make

Answer 6

ATP

Question 7

What relies on glucose

Answer 7

Neurons and red blood cells (RBCs) rely almost entirely upon glucose

Question 8

Excess glucose is converted to

Answer 8

glycogen or fat and stored

Question 9

Triglycerides

Answer 9

Saturated fats in meat, dairy foods, and tropical oils

Unsaturated fats in seeds, nuts, olive oil, and most vegetable oils

Question 10

Essential fatty acids

Answer 10

Linoleic and linolenic acid, found in most vegetable oils

Must be ingested

Question 11

Essential uses of lipids in the body

Answer 11

Help absorb fat-soluble vitamins

Major fuel of hepatocytes and skeletal muscle

Phospholipids are essential in myelin sheaths and all cell membranes

Question 12

Functions of fatty deposits (adipose tissue)

Answer 12

Protective cushions around body organs

Insulating layer beneath the skin

Concentrated source of energy

Question 13

Regulatory functions of prostaglandins

Answer 13

Smooth muscle contraction

Inflammation

Control of blood pressure

Question 14

Functions of cholesterol

Answer 14

Stabilizes membranes

Precursor of bile salts and steroid hormones

Question 15

Structural materials:

Answer 15

keratin, collagen, elastin, muscle proteins

Question 16

Use of amino acids in the body

Answer 16

All-or-none rule
Adequacy of caloric intake
Nitrogen balance
Hormonal controls

Question 17

All-or-none rule

Answer 17

All amino acids needed must be present for protein synthesis to occur

Question 18

Adequacy of caloric intake

Answer 18

Protein will be used as fuel if there is insufficient carbohydrate or fat available

Question 19

Nitrogen balance

Answer 19

State where the rate of protein synthesis equals the rate of breakdown and loss

Positive if synthesis exceeds breakdown (normal in children and tissue repair)

Negative if breakdown exceeds synthesis (e.g., stress, burns, infection, or injury)

Question 20

Hormonal controls

Answer 20

Anabolic hormones (GH, sex hormones) accelerate protein synthesis

Question 21

What do Vitamins function as

Answer 21

coenzymes

Question 22

Which vitamins have been made in the body?

Answer 22

Vitamins D, some B, and K are synthesized in the body

Question 23

Two types of vitamins based on solubility

Answer 23

Water-soluble vitamins
Fat-soluble vitamins

Question 24

Water-soluble vitamins

Answer 24

B complex and C are absorbed with water

B12 absorption requires intrinsic factor

Not stored in the body

Question 25

Fat-soluble vitamins

Answer 25

A, D, E, and K are absorbed with lipid digestion products Stored in the body, except for vitamin K Vitamins A, C, and E act as antioxidants Prevent oxidative damage

Question 26

Seven required minerals

Answer 26

Calcium, phosphorus, potassium, sulfur, sodium, chloride, and magnesium

Question 27

How to prevent toxic overload

Answer 27

Uptake and excretion must be balanced

Question 28

What do minerals do

Answer 28

Work with nutrients to ensure proper body functioning

Question 29

Define metabolism

Answer 29

Metabolism refers to all chemical reactions in an organism Biochemical reactions inside cells involving nutrients

Question 30

Cellular Metabolism

Answer 30

Includes all chemical reactions within cells Provides energy to maintain homeostasis and perform essential functions

Question 31

Essential Functions of metabolism

Answer 31

Metabolic turnover: Periodic replacement of cell’s organic components Growth and cell division Special processes, such as secretion, contraction, and the propagation of action potentials

Question 32

Two types of metabolic reactions

Answer 32

Anabolism: synthesis of large molecules from small ones (Building up) Catabolism: hydrolysis of complex structures to simpler ones (Breaking down)

Question 33

Cellular respiration

Answer 33

catabolism of food fuels and capture of energy to form ATP in cells

Question 34

phosphorylation

Answer 34

Enzymes shift high-energy phosphate groups of ATP to other molecules

Question 35

Why are phosphorylated molecules activated

Answer 35

to perform cellular functions

Question 36

Stages of Metabolism

Answer 36

Digestion, absorption and transport to tissues Cellular processing (in cytoplasm) Synthesis of lipids, proteins, and glycogen, or Catabolism (glycolysis) into intermediates Oxidative (mitochondrial) breakdown of intermediates into CO2, water, and ATP

Question 37

Oxidation

Answer 37

gain of oxygen lose electrons and energy

Question 38

Reduced substances

Answer 38

gain electrons and energy

Question 39

Coenzymes

Answer 39

NAD+ - reduced to NADH FAD - reduced to FADH2

Question 40

ATP Synthesis

Answer 40

Substrate-level phosphorylation Oxidative phosphorylation

Question 41

Substrate-level phosphorylation

Answer 41

phosphate groups directly transferred from phosphorylated substrates (high energy intermediates) to ADP (adenosine diphosphate) to synthesise ATP

Question 42

glycolysis occurs in Krebs cycle occurs in

Answer 42

(in cytoplasm) Mitochondria

Question 43

Oxidative Phosphorylation

Answer 43

Production of ATP from the oxidized NADH and FADH2 Made up of two components: electron transport chain and chemiosmosis

Question 44

Chemiosmotic process

Answer 44

Couples the movement of substances across a membrane to chemical reactions Carried out by electron transport proteins Nutrient energy is used to create H+ gradient across mitochondrial membrane H+ flows through ATP synthase Energy is captured and attaches phosphate groups to ADP

Question 45

Glucose is catabolized in three pathways

Answer 45

Glycolysis Krebs cycle Electron transport chain and oxidative phosphorylation