Energy in Cells: Storing Energy

Herndon

Autotroph• Obtains energy from sunlight or inorganic

compounds• Also called a producer• Uses photosynthesis to acquire food• Some use chemosynthesis to acquire food-

use inorganic compounds• Examples: algae, blue-green bacteria, plants,

and some prokaryotic organisms

Heterotroph • Can’t make its own food• Gets energy from other food sources• Also called consumers• Primary consumer, secondary consumer,

tertiary consumer• Animals, fungi, some bacteria and some

protists

Photosynthesis • Process in which plants convert the energy

from the sun into chemical energy• Carbon dioxide + water + sunlight glucose +

oxygen• Plants gather sunlight with pigments in the

leaves that absorb sunlight• Chlorophyll is the primary pigment• Chlorophyll absorbs mostly blue and red light

and reflects green light

• The yellow and green light reaches your eyes and that is the reason why plants look green

• When a substance absorbs light, it also absorbs the energy of the light

• Chlorophyll is located in the chloroplasts of a plant

• Most of the chloroplasts are located in the leaves

Parts of the chloroplast• Inner and outer membranes• Stroma • Granum• Thylakoid- contains clusters of chlorophyll and

other pigments

Light dependent stage • The direct energy of light is needed to make

energy-carrier molecules that are used in the second stage

• Happens in the thylakoid membrane• Energy of the light absorbed is converted into

ATP and NADPH• Which are energy carriers

Calvin cycle• Second stage of photosynthesis• Takes place in the stroma of the chloroplast• Can occur in the dark• Needs the products of the light dependent

reaction• Carbon dioxide and energy from ATP are used to

form glucose• Six molecules of carbon dioxide are used to form

one glucose

Factors that Affect Photosynthesis

• Water• Amount of sunlight• Temperature• There is a maximum rate for photosynthesis• Enzymes needed for the reaction must be in a

certain temperature range

Review • Capsid is not part of a eukaryotic cell• Ribosomes are attached to the rough ER for

protein production• Active transport takes energy• Carbon is in all organic compounds• Amino acids are the building blocks of

proteins