Chapter 9 Flashcards
Define nutrient
a chemical that must be obtained by an organism from its environment in order to survive
Food for Growth and Maintenance
- carbohydrates
- proteins
- lipids
- water
- vitamins
- minerals
Broken down into simpler molecules that are used to build and repair bone, muscle, cells, and tissues.
Food for Energy
- all organisms need chemical energy
- humans obtain chemical energy carried in animal and plant-based foods
- cells in the body use chemical energy to fuel biological processes
Define metabolism
a set of chemical reactions that occur in living organisms that are necessary to maintain life
Define catabolism
the metabolic reactions that break down larger molecules into smaller subunits
Define anabolism
the metabolic reactions that use energy to produce larger molecules from smaller subunits
Metabolic rate
the rate at which the body converts stored energy into working energy
Factors that affect metabolic rate
- body size
- physical activity
- sex
- age
- hereditary factors
Measuring energy
1 calorie = 4180 J
Define macronutrients
a substance required in relatively large amounts by living organisms
- carbs, lipids, proteins, water
Define micronutrients
a chemical element or substance required in very small amounts by living organisms
- vitamins, minerals
Macronutrients: carbohydrates
- when we digest carbohydrates, they are broken down into simple sugar (monosaccharides)
- made up of C, H, O
- main energy source
- foods high in carbs are vegetables, fruits, potatoes, grains
3 types - Monosaccharides (ie. glucose)
- Disaccharides (ie. sucrose, table sugar)
- Polysaccharides (ie. cellulose, starch)
Macronutrients: protein
- when we digest proteins, they are broken down into amino acids
- made up of C, H, O, N
Functions - building blocks of cells
- involved in movement and biochemical reactions
- hormones
- enzymes
20 different types of amino acids - 12 non essential (can be made by the body)
- 8 essential (ie. through food)
Foods high in protein are meat, eggs, cheese, nuts
Macronutrients: lipids
- when we digest triglycerides (fats and oils), they are broken down into fatty
- made up of C, H, O
Functions - secondary source of energy after carbohydrates
- helps with absorption of vitamins
- insulation for the body
- some types of hormones
Saturated vs. Unsaturated fats
Saturated fats
- usually solid at room temp
- considered to be less healthy
- ie. butter
Unsaturated fats
- usually liquid at room temp
- considered to be more healthy
- ie. vegetable oil