Chapter 5

Intro to Metabolism

Metabolism: chemical reactions in body’s cells that change food into energy

• Anabolism: builds; building proteins using amino acids. Uses energy

• Catabolism: destroys; breaking down glucose from food to form ATP. Uses and Produces energy

Energy: ability to do work; ability to cause some kind of change

• Ex: light, heat, electricity

Autotroph

• Make own food using sun’s energy

• Producers

• Ex: plants

Heterotroph

• Don’t make own food, eats others for energy

• Consumers

• Ex: animals

Trophic Levels: an organism’s place in the food chain

Higher levels - less energy from food

Lower levels - more energy from food

• Producers

  • Make their own food

  • Ex: plants, algae

• Primary Consumers

  • Herbivores

  • ‘Plant eaters’

• Secondary Consumers

  • carnivores/omnivores that eat herbivores (primary consumers)

• Tertiary Consumers

  • Carnivores that eat other carnivores/omnivores

• Quaternary Consumers

  • Apex predators

  • Ex: lions, polar bears

• Decomposers

  • Decompose dead things

  • Ex: plants, bacteria, fungi, insects

Trophic levels aren’t set in stone. Organisms can eat certain things that change which trophic level they’re in.

Kinetic Energy: the energy of motion

Potential Energy: stored energy related to its position

Chemical Energy: energy stored in chemical bonds

Energy Conversions: light bulbs change electrical energy into heat and light energy

Law of Thermodynamics

Thermodynamics: the study of heat and other energy forms

Characteristics we see with energy

1. Energy can’t be created or destroyed

   1. Universe will always have the same amount of energy

2. Energy tends to disperse

   1. Hot things will always cool down aka lose energy

Energy in Biology

Biochemical reactions: molecules changing into other molecules

Exergonic

Energy releasing

Spontaneous (doesn’t need energy)

Ex: cellular respiration

Endergonic

Energy consuming

Need energy (ex. sunlight)

Ex: photosynthesis

Reactants: molecules entering a reaction to be changed

Products: molecules produced by reaction

Activation energy: minimum amount of energy needed to start a chemical reaction