Cells Unit 3 Cell Membrane and Cell Transport

Cells Unit 3

Cell Membrane and Cell Transport

Notes: Cell Membrane Structure • The cell or plasma membrane is also known as the PHOSPHOLIPID BILAYER since it has 2 layers. ________________ FLUID MOSAIC MODEL • It is known as a _______ since it is made up of many parts and is not rigid and moves easily. • The main function of the cell membrane is to maintain homeostasis by controlling ______________ WHAT GOES IN AND OUT • The cell membrane doesn’t let everything through. It is SELECTIVELY PERMEABLE _________________and only lets certain things in and out.

Cell Membrane Diagram Video – Cell membrane INTEGRAL PROTEINS CARB CHAIN PHOSPHATE HEAD FATTY ACID TAILS PHOSPHOLIPID CHOLESTEROL PERIPHERAL PROTEIN

Osmosis wa in r out shrink Isotonic solution equal Less than te te r greater Hypotonic solution wa Hypertonic solution grow r e t wa in / out Stay same size

Concentration Gradient • Differences in concentration on either side of a membrane.

Hill Diagram Active Transport -Goes against the concentration gradient (low to high) -– needs energy (ATP) High/More • P = Pump – solute (dots) through a protein • E = Endocytosis – move into cell High / • E = Exocytosis – move out of cell More Low/Less Passive Transport -Goes with the concentration gradient (high to low) - no energy • D = Diffusion – solute (dots) move (Ex: salt) • O = Osmosis – water moves • F = Facilitated Diffusion – solute (dots) move through protein Low/Less

DIFFUSION – dots such as salt are moving. OSMOSIS - dots can’t move so water moves to dilute the dots FACILITATED DIFFUSION – dots are too big or polar so need to go through a protein

Which way will things move? Given the pictures below, draw arrows in the correct direction to show what will move. You need 4 different colors to make your key: Diffusion – Red Facilitated diffusion – Green Osmosis – Blue Pump (active transport) – Purple

Real life scenarios – What will happen? ? ? 1. A saltwater fish is placed into fresh water. What will happen to the cells of this fish? Water will move in and the fish’s cells will grow. 2. A freshwater fish is placed into a salt water tank. What will happen to the cells of this fish? Water will move out and the fish’s cells will shrink.

Explain the following picture. Salt on a slug will cause water to move out of the slug to dilute the salt on the outside of the body. The slug will dehydrate and die.

Understanding Osmosis & Diffusion (Passive Transport) Hypo = less Hyper = more Iso = same When answering the questions, consider the following information: • The oval in each diagram below represents a cell. • The black line around the oval is the cell membrane. • The space between the dots represents the water (solvent) that the solute is dissolved in. • The solute (dots) AND solvent (water) is small enough to pass across the cell membrane. Cell #1 Cell #2 Cell #3

CONCENTRATION DIFFERENCES: 1. The solution outside cell #1 has a/an (higher; LOWER; equal) concentration of solute compared to the solution inside the cell. 2. The solution outside cell #1 is (hypertonic; HYPOTONIC; isotonic) to the solution inside the cell. 3. The inside of cell #1 is (HYPERTONIC; hypotonic; isotonic) to the solution surrounding it. 4. The solution outside cell #2 has a/an (HIGHER; lower; equal) concentration of solute compared to the solution inside the cell. 5. The solution outside cell #2 is (HYPERTONIC; hypotonic; isotonic) to the solution inside the cell. 6. The inside of cell #2 is (hypertonic; HYPOTONIC; isotonic) to the solution surrounding it. 7. The solution outside cell #3 has a/an (higher; lower; EQUAL) concentration of solute compared to the solution inside the cell. 8. The solution outside cell #3 is (hypertonic; hypotonic; ISOTONIC) to the solution inside the cell.

DIFFUSION: 9. If diffusion was to occur to cell #1, in which direction would most of the solute be moving? (into /OUT OF) the cell. 10. If diffusion was to occur to cell #2, in which direction would most of the solute be moving? (INTO /out of) the cell. 11. Describe what happens to the movement of solute for cell #3. THE SOLUTE WOULD MOVE IN AND OUT. 12. Due to the process of diffusion, the solute or dissolved material tries to move from an area of higher concentration into an area of lower concentration (someplace where it can spread out more). According to this statement, which of the above cells would lose the most solute due to diffusion? (CELL #1, CELL #2, CELL #3)

OSMOSIS: 13. If osmosis was to occur in cell #1, which direction would most of the water be moving? (INTO /out of) the cell. 14. Cell #1 should have (lost ; GAINED; stayed the same) mass. 15. If osmosis was to occur in cell #2, which direction would most of the water be moving? (into /OUT OF) the cell. 16. Cell #2 should have (LOST ; gained; stayed the same) mass. 17. If osmosis was to occur in cell #3, which direction would most of the water be moving? (INTO & OUT OF) the cell. 18. Cell #3 should have (lost ; gained; STAYED THE SAME) mass.

WHAT DOES THIS MEAN… 19. Since an animal cell lacks a cell wall, it is important that it be surrounded by a/an (hypertonic; hypotonic; ISOTONIC) solution, so that it does not shrink & shrivel up or swell & rupture due to the effects of osmosis. 20. If red blood cell is surrounded by a hypotonic solution, then the cell would most likely (shrink, SWELL or stay the same size). 21. When plant cells are full of water, the pressure within the cell pushes out onto the cell wall, thus allowing the cell to become more rigid (has turgor pressure). Since this is a good thing for them, plant cells should be surrounded by a/an (hypertonic; HYPOTONIC; isotonic) solution.

Prokaryotic vs. Eukaryotic Cells: SMALL Prokaryotic cells - __________, no nucleus and no MEMBRANE BOUND _________________ organelles. BACTERIA Ex: ______________ LARGER NUCLEUS Eukaryotic cells - _________, have a _________ PLANTS & ANIMALS and membrane bound organelles. Ex: _____________

No matter what, all cells have 4 organelles in common: CELL MEMBRANE _________________ DNA _________________ CYTOPLASM _________________ RIBOSOMES _________________

Notes: Cell Theory • All living things are made up of one or more CELLS _______. • All cells come from _____________ cells. PREEXISTING • Cells are the basic unit of structure and function of an organism.

How did the first Eukaryotic cells come about? Endosymbiosis Animation

How did the first Eukaryotic cells come about? • Endosymbiosis Theory - endo means _________, INSIDE RELATIONSHIP symbiotic means ______________ so…… PROKARYOTES • Smaller _____________ entered inside larger prokaryotes. The smaller prokaryote(s) got PROTECTION ____________ and the larger prokaryote got ENERGY (ATP) ________________________. These MITOCHONDRIA organelles eventually became the ___________ and CHLOROPLAST ______________

Cell Specialization STEM CELLS SPERM CELL FLAGELLUM RED BLOOD CELL NERVE CELL

NOTES: ORGANELLES ORGANELLE • An _________is a tiny structure that performs a specialized function (or job) in the cell. Ex: nucleus, chloroplast, mitochondria, ribosome, cell membrane, cell wall, vacuole

CELL WALL (in plants only) Cell Membrane Cell Wall Structure & support Wall around the kingdom – extra support

CHLOROPLAST Site of photosynthesis – uses light to make CHLOROPLAST sugar (glucose) (in plants only) Farmers – use light to grow (make) food

VACUOLE Stores things Plant – Large central like water and nutrients Animals – many small Vacuole Nucleus Well – stores water

CELL MEMBRANE Cell Membrane Controls what enters and leaves the cell Knights at the gate– control what goes in and out

MITOCHONDRIA Site of cellular respiration - turns MITOCHONDRIA sugar (glucose) into useable energy (ATP) Chefs– make food useable by cooking it

NUCLEUS Nuclear Envelope Protects genetic info DNA = King NUCLEUS = Castle DNA

RIBOSOMES Where proteins are made Town workers – make things

PROKARYOTIC VERSUS EUKARYOTIC No membrane bound organelles Has a nucleus Has DNA No nucleus Has cytoplasm Ex: Plants & Animals Has cell membrane Has ribosomes Ex: Bacteria Has membrane bound organelles

PLANT VERSUS ANIMAL chloroplasts Large central vacuole nucleus ribosomes Membrane bound organelles cell membrane cytoplasm Cell wall No cell wall mitochondria eukaryotic Small vacuoles

Microscopes • How do we see cells and organelles? ? ? • _____________________________ COMPOUND LIGHT MICROSCOPE uses 2 lenses and light to magnify an image up to 2000 x. Can look at living cells. • Total magnification = ocular lens x objective lens • Ex: Ocular is 10 x and Objective is on 40 x, what is total magnification? 10 x 10 = 100 • STEREOMICROSCOPE/DISSECTING SCOPE ___________________ - used to view larger objects. Magnifies up to 50 x. Can look at living cells. ELECTRON MICROSCOPE • ___________________ - can magnify up to 200, 000 x but specimen must be dead. • Make sure to study your Microscope Lab to learn more about the parts and functions of the microscope. This will be on your test!

COMPOUND LIGHT MICROSCOPE