Test Review Debrief

That cells are made of smaller organelles that perform different functions for the cell (ex. Mitochondria (provide power), ribosomes (make proteins) What have we learned about cells as technology has improved? (example: More powerful microscopes)

Multicellular organisms (like you) have specialized cells (liver, skin, bone, etc.) that carry out different functions needed to survive. How are multicellular organisms different from single-celled organisms? Allows multicellular organisms to be much larger than single-celled organisms

#5

All cells contain: Cell membrane (selectively permeable: lets some stuff in or out) Cytoplasm (watery goo-like substance; fills the cell like air in the room) DNA (the cell’s instructions) Ribosomes (Make the different proteins needed by the cell to function) What structures do all cells contain?

macro

All three have a cell membrane but plants and bacteria also have a cell wall (made of different materials). Bacteria (prokaryotes) don’t have a membrane-bound nucleus and are much smaller and simpler. Plants have specialized water storage structures and chloroplasts.

#10

#13

This allows multicellular organisms to be much larger than single-celled organisms.

What’s the Key Idea here? The next few slides go over the key concepts for the second part or the unit. Cell Membranes are Selectively Permeable (controls what enters and exits the cell).This is how cells can regulate what goes in and out of the cell.

Osmosis!!! An egg in distilled water will absorb water through the membrane because the concentration of water is higher outside the egg than inside. An egg in salt/sugar water will lose water because the concentration of water is lower outside the egg than inside. Why do eggs (w/o shell) expand in distilled water and shrink in salt or sugar water?

#19

Active transport is the movement of a substance against its concentration gradient (from low to high concentration). In all cells, this is usually concerned with accumulating high concentrations of molecules that the cell needs, such as ions, glucose and amino acids. Passive transport means substances across membranes. Unlike active transport, this process does not involve chemical energy. So passive transport is dependent on the permeability of the cell membrane.

The cell membrane or plasma membrane separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cell. It basically protects the cell from outside forces

Heat energy (molecules moving faster) helps speed up diffusion

Both liquids (urine and water) would spread out on their own through diffusion using internal energy. end show

How do I know if something is “living”? It contains cells (one or more). ALL living things contain cells! It’s simple: Without cells = it’s not “living”.