Question | Answer |
What do cells get from their environment? | food, oxygen, water, and other substances |
What do cells release from their environment | waste materials |
Materials are moved into and out of the cells by the ____________. | cell membrane |
What does it mean by "cell membranes are semipermeable?" | It means that some materials can pass through and others cannot and they act like a kitchen strainer |
True or False: Do cell membranes have pores like our skin that allow small particles to pass through, but the larger particles get trapped and cannot pass through the membrane? | True |
True or False: Are molecules not constantly on motion? | False: molecules are constantly on motion and as they move they spread out or diffuse |
Diffusion | when particles move from an area of high concentration to low concentration (particles move from where there were many to where there are few) |
What is diffusion also called? | passive transport |
Does this process use energy? | NO! |
What is and example of diffusion | food coloring spreading in water |
Equilibrium | molecules of a substance are spread out evenly throughout a space and the molecules continue to move |
Osmosis | the diffusion of water across a membrane |
Active transport | is the opposite of diffusion; particles move from an area of low concentration to high concentration (from where there are few to where there are many |
Does active transport use energy? | yes |
Active transport also includes... | the movement of LARGE particles across a membrane |
Example of active transport | plant cells taking in minerals from the soil even though they already have lots of minerals |
Endocytosis | the cell membrane folds to make a sphere around excessively large molecules; the sphere pinches off and forms a vacuole with the molecules in side; the vacuole floats around in the cytoplasm |
Example of endocytosis | the cell membrane uses this process to allow large materials to enter the cell |
Exocytosis | the Golgi bodies move packaged waste products to the cell membrane; the package fuses to the cell membrane; wastes are released outside the cell |
Where do organisms get their energy? | from the food they eat and cells that take chemical energy stored in food and change it into other forms so it can be used during metabolism |
Metabolism | the total of all chemical reactions that take place in an organism |
Examples of metabolism | photosynthesis, respiration, digestion |
What are the two groups that organisms are divided into? | producers and consumers |
Producers | organisms that can make their own food |
Ex. of producers | plants |
Consumers | organisms that cannot make their own food |
Ex. of consumers | animals and fungi |
Photosynthesis | the process that producers use to change light energy from the sun into chemical energy that cam be used |
What does the energy in the sun change? | it changes carbon dioxide and water into glucose (sugar) and oxygen |
What is glucose? | used as food by the plant |
What is oxygen given off as? | waste products |
Chlorophyll | a green pigment that traps the sunlight |
Where does photosynthesis take place? | in the chloroplasts |
What is the chemical equation for photosythesis? | energy + 6H2O + 6CO2 -> C6H12O6 + 6O2
energy + water + carbondioxide -> glucose + oxygen |
What do consumers have to do to take in stored energy from food? | eat producers (plants) or eat other consumers who have eaten plants |
A food chain shows... | the flow of energy throughout the ecosystem |
Respiration | all living things do it to release energy from food; all organisms nee some way of releasing energy from food to be able to use it |
Aerobic respiration | requires energy |
Where does aerobic respiration take place? | the mitochondria |
What happens during respiration? | food molecules (glucose) and oxygen get broken down and carbon dioxide, water, and energy (ATP) are given off as waste products |
Is respiration the opposite of photosynthesis? | yes |