How Substances Move Into and Out of Cells

How things move in and out of a cell Cells are constantly moving things in and out: gases, food, water, wastes The cell membrane is the structure in the cell that allows this to happen. It is a semipermeable membrane.

How things move in and out of a cell There are two main ways that cells move substances Diffusion Osmosis

How things move in and out of a cell Diffusion: The movement of particles from an area of high concentration to low concentration The particles are spreading out evenly

How things move in and out of a cell Osmosis: the diffusion of water The amount of water in the cell needs to be a certain level. So if there is too much inside they need a way to get some out. If there is too little inside they need a way to get some in.

Osmosis in blood cells

Practice Questions 1. The terms diffusion and osmosis seem to have similar meanings. Explain how they are similar. Then give a reason why scientists use two separate terms. 2. Martin volunteered to carry drinks to the class hosting a surprise party for a retiring teacher. He isn’t sure which classroom is the right one, but he does know the students plan to serve pizza and popcorn. Explain how Martin could use the smell as a clue.

Cells in multicellular organisms combine to form tissues and organs

How cells reproduce

Multicellular organisms have specialized cells. Which means the cells have specific jobs that they do to support life. The cells have developed structures to help them do their jobs. For example blood cells have to carry oxygen to small places so their thin, pliable disc shape helps them do this.

Animal tissue Similar cells form together to create tissue. There are 4 different types: connective, epithelial, nervous and muscle Organs are made up of a combo of these four tissues.

Animal Tissue Connective tissue: supports and connects different parts of the body. Blood is a connective tissue and so is fat , cartilage, bones and tendons Epithelial tissue: covers the surface of your body and the outside of your organs. it also lines the inside of some of the organs Nervous tissue: makes up the brain spinal cord and nerves Muscle tissue: allows you to move. One type of muscle allows you to move your body. Cardiac muscle tissue pumps blood through your heart, and smooth muscle moves food along your intestine.

Plant tissue Plants have 3 types of tissue: photosynthetic/storage, protective, and transport These types of tissues are organized to for the three organs of a plant. leaves roots stem Plants do not have organ systems but the organs do still interact with each other.

plant tissue Turn to page 123 of textbook Leaf Protective tissue: waterproof layer, protect the plant Transport tissue: tube like cells with hollow centre, phloem transports food, xylem transports water Photosynthetic tissue: use sunlight to produce sugar that the plant uses for energy

Plant Tissue See page 124 Stem Protective tissue: waterproof and protective layer Transport tissue: phloem- food, xylem- water Storage: support plant and store food

plant tissue See page 124 Root Protective tissue: absorb water from soil Transport tissue: brings in water and nutrients Storage tissue: stores food