Chapter 8-1: Energy & Life

Autotrophs and Heterotrophs (a review) all energy comes from the sun Organisms get their energy in two ways autotrophs: plants and other organisms that can make their own food heterotrophs: organisms that obtain energy by consuming other organisms

Autotrophs Sunlight is the main energy source for life on Earth. Some organisms rely on energy stored in inorganic chemical compounds… Water can be loaded with chemical energy! Autotrophs: organisms that can make their own food. Ex: plants! They use sunlight, water and CO2 to make energy and oxygen… PHOTOSYNTHESIS

Heterotrophs Types of consumers/heterotrophs Herbivores: obtain energy by eating plants. Carnivores: obtain energy by eating animals. Omnivores: obtain energy by eating plants and animals. Detritivores: obtain energy by feeding on plant/animal remains or other dead matter. Decomposers: organisms that break down organic matter for energy. Ex: some bacteria and fungi

Chemical Energy and ATP three types of energy (heat, light, and chemical) Food stores a lot of the chemical energy Food is not an usable form of chemical energy in cells It must be converted to a usable form Food is changed into: adenosine triphosphate (ATP): chemical fuel that powers cell’s activities

ATP: Adenosine Triphosphate

ATP is converted to ADP when terminal phosphate bond is broken and energy is released ADP = Adenosine Diphosphate (2 phosphates instead of 3) ADP is converted to ATP when a high energy phosphate is added (energy is stored) ATP ADP + P

releasing energy from ATP the energy released from ATP is used to power a variety of cellular activities using biochemical energy powers active transport powers the sodium-potassium pump powers movement of organelles within the cell

ATP and Glucose (sugar) cells only store small amounts of ATP (inefficient for storing energy) energy from carbohydrates used to regenerate ATP from ADP as needed

Chapter 8 Study Guide Complete questions 5 – 22 Due tomorrow!