Lesson 2: Metabolism

Question 1

what is metabolism?

Answer 1

process where your body converts the foods you eat into energy

Question 2

what is BMR?

Answer 2

basal metabolic rate; it is essentially the amount of calories you burn at rest by doing absolutely nothing- it does not include the calories you burn by exercise, etc.

Question 3

what does metabolism exactly do in the body?

Answer 3

• performs chemical reactions such as digestion, etc

Question 4

what are the types of reactions metabolism is made up of? what are they?

Answer 4

catabolic: breakdown of materials in an organism (ex: enzymes break down large nutrients into smaller ones)
anabolic: building of complex materials from simpler ones (amino acids are built together to make complex molecules)

Question 5

do all living things require the same amount of energy? how do you know?

Answer 5

do not require the same amounts of energy
- endothermic animals like mammals and birds require more energy as they use this energy to keep their bodies warm
- ectothermic animals like reptiles do not require a high amount of energy as they are colder blooded: they do not need energy to keep them warm

Question 6

what are some ways to lose weight?

Answer 6

• exercise (burns cals right away and continues to burn cals during sleep)
• dont skip meals (starving yourself makes your brain only think of eating high calorie foods)
• more protein and low fat dairy (supresses hunger)
• eating soups: liquified food/liquids are harder to absorb, so you are less hungry
• count calories (helps keep track of healthy cals)
• sleep deprivation and stress levels can make you hungrier

Question 7

what affects metabolism?

Answer 7

body size:
- larger the body, more energy is required
physical activity:
- muscles burn more energy than fats, so active people require more energy
age:
- metabolic rate decreases with age
sex:
- biological males are bigger than biological females so they need more energy
heredity factors:
- naturally higher or lower metabolic rates due to genetics
disease:
- disorders with the thyroid (hyperthyroidism, hypothyroidism)

Question 8

What are thyroids? what are they made of?

Answer 8

very important gland that produces hormones which controls the way the body uses energy
- made up lobules, which contain smaller cells called follicles;

Question 9

what do follicles do?

Answer 9

store the hormones that the thyroid sends out into the blood called follicular cells- 2 main hormones are produced: T3 and T4

Question 10

What are the hormones job?

Answer 10

instructs every cell when to consume oxygen and nutrients, which MAINTAINS the body’s metabolism

Question 11

what do thyroids do to increase metabolism?

Answer 11

they send out hormones that allows our cells to use energy, grow, and reproduce

Question 12

what are thyroids controlled by? what do they do?

Answer 12

pituitary glands: they sense if hormone levels in blood are too high or too low

Question 13

what is hyperthyroidism? how does it occur?

Answer 13

happens when organ sends out too many hormones by becoming “deaf” to the pituitary commands

Question 14

What exactly happens when too many hormones are sent out? how does it affect metabolism?

Answer 14

cells become overloaded with instructions to consume more nutrients and oxygen- this inflicts a higher metabolism which makes someone hungrier, lose weight, etc.

Question 15

what is hypothyroidism? how does it affect metabolism?

Answer 15

when not enough hormones are sent out- metabolism slows which makes someone gain weight, and feel weaker

Question 16

what is the standard unit for measuring energy?

Answer 16

joule (J); this is a very small unit, so we usually measure energy in kilojoules (kJ)

rather than showing joules on nutrition labels, calories is shown

Question 17

what do calories tell you?

Answer 17

how much energy you’ll obtain from the food
- one calorie= amount of energy that is required to raise one gram of water by one degree celcius
- on nutrition labels, it is usually kilocalories rather than calories (1 kC = 4180 J)

Question 18

how many and what are the ways that energy is used in the body?

Answer 18

10% digestion, 20% physical activity, 70% basic functions of organs and tissues

Question 19

how does the amount of calories an individual needs daily differ?

Answer 19

• if you exercised a lot in a day, you might need 9000 cals that day rather than a regular amount
• if pregnant, you’ll require more calories than usual
• if you are older, you have a lower metabolic rate, which means you require less calories

Question 20

how does every individuals ability to extract energy from food differ?

Answer 20

• enzyme levels
• gut bacteria
• intestine length

Question 21

factors that affect BMR

Answer 21

• body composition (muscular person has higher BMR than regular)
• age (bmr decreases with age and younger people have higher bmr’s)
• gender (men have more muscle therefore higher bmr)
• climate (colder the temp, higher the bmr)
• size (larger person has higher bmr)

Question 22

what diets work and what diets dont?

Answer 22

• low fat diets have been proven not to work
• low carb diets work better (less likely for heart disease; lowers triglycerides, raises good cholesterol)

Question 23

how do you maintain a healthy lifestyle?

Answer 23

its all about good balance between
- what you are eating
- how much you are eating
- how much physical activity you do
too much or too little of everything is never good: too much eating, exercise, is not healthy while too little eating and exercise is not healthy too. you must maintain good balance between healthy lifestyle choices

Question 24

what does it mean to be bullimic? what can it do to a person?

Answer 24

eating too little, starving yourself
- it can risk heart attacks
- stomach problems
- esophagus is in danger