S UN W ORSHIP

W E C AN ’ T L IVE W ITHOUT T HEM Biological activity requires a source of energy. Cellular respiration produces ATP. Plants use some o f the ATP molecules they make to power the biochemical reactions that sustain life. Create more tissue (e.g., leaves) The energy to power these reactions comes from the SUN! Organisms that produce their own food are called producers. Plants are producers because they make their own food.

W E C AN ’ T L IVE W ITHOUT T HEM Animals can’t create their own food. Why? Organisms that can’t create their own food are called consumers. Consumers obtain the energy they need by eating other organisms. Herbivores = animals that eat plants Plant tissues contain many energy-rich molecules – sugars, fats, proteins Digestion breaks down the molecules that make up the plant. Cellular respiration releases the energy that was stored in the bonds of the molecules in plants and produces ATP. Herbivores use the energy for movement and growth All the energy originally came from the SUN!

W E C AN ’ T L IVE W ITHOUT T HEM Carnivore = animal that eats other animals Omnivore = animal that eats plants and animals The tissues of animals are made up of energy-rich molecules – sugars, fats, proteins. Digestion breaks down the molecules that make up the meat. Cellular respiration releases the energy that was stored in the bonds of the molecules in animals and produces ATP. Carnivores/Omnivores use the energy for movement and growth (building new body tissues) All the energy originally came from the SUN!

W E C AN ’ T L IVE W ITHOUT T HEM Heterotrophs are organisms that obtain their energy from other organisms. They can’t make their own food Examples: animals, fungi, bacteria Autotrophs are organisms that can create their own food from nonliving sources, such as the Sun, air, and minerals. Examples: plants, some bacteria How are they related? Autotrophs provide the energy and organic molecules needed for maintenance and growth of heterotrophs.

W E C AN ’ T L IVE W ITHOUT T HEM Demo: Calorie in a cheetoh We measure the amount of energy in food using a unit called the Calorie. What do burning foods give off? How is burning the food similar to what happens during cellular repiration? Why does burning different foods produce different results?

E NERGY B UDGET What do you notice about the amount of energy transferred from one organism to another?

B IOSYNTHESIS AND B REAKDOWN Metabolism – all of the chemical activities and changes that take place in a cell or an organism Cells have two types of metabolism: Biosynthesis reactions – build larger, more complex molecules from smaller, less complex molecules Examples: build proteins from amino acids, build tissues from proteins, photosynthesis Require energy Breakdown or decomposition reactions – break down larger molecules into smaller molecules Examples: break starch into glucose, cellular respiration Release energy

B IOSYNTHESIS AND BREAKDOWN Food provides the energy needed for biosynthesis reactions. Food also provides the organic molecules that organisms need to make sugars, amino acids, proteins, etc. Plants make organic molecules from the sugars that are made in the Calvin Cycle Animals get the organic molecules they need by breaking down their food through digestion Enzymes in the mouth, stomach and small intestine help to break food down into usable organic molecules: Sugars, amino acids, glycerol, fatty acids Organic molecules can enter various stages of cellular respiration to create energy Organic molecules can also be used in biosynthesis reactions to create molecules needed for maintenance and growth of the organism.

R EFLECT AND C ONNECT P. 353 List 3 examples of biosynthesis reactions List 3 examples of breakdown reactions Why are biosynthesis and breakdown reactions important for organisms?