Cells Packet 4 Notes Cell Membrane Structure The

Cells Packet 4

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 CHOLESTEROL INTEGRAL PROTEINS CARB CHAIN PHOSPHATE HEAD FATTY ACID TAILS PHOSPHOLIPID PERIPHERAL PROTEIN

Parts of the Membrane: LIPIDS TYPES: Phospholipids FUNCTION: PICTURES: Polar, hydrophilic heads Nonpolar hydrophobic fatty acid tails Polar versus Nonpolar Polars and nonpolars DON’T mix!!! Cholesterol (Steroids) Keep the membrane ______ FLUID

Parts of the Membrane: PROTEINS TYPES: Integral FUNCTION: GO ALL THE WAY THROUGH THE MEMBRANE TO TRANSPORT Peripheral _________THINGS ON THE EDGE OF THE RECEIVE SIGNALS MEMBRANE TO CARBOHYDRATES IDENTIFY A CELL _______ (NAME TAG) PICTURES:

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

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

Miscellaneous terms a solution with a higher concentration than another solution. (Water out & cell will HYPERTONIC shrink) HYPOTONIC a solution with a lower concentration than another solution. (Water in & cell will grow) r Part of a solution that does the dissolving (Water) te SOLVENT The dots are the solute and solvent is the white space or water. The water dissolves the dots. wa SOLUTE Part of a solution that is dissolved (Salt) r te a w

Miscellaneous terms ISOTONIC a solution with an equal concentration to another solution (Water moves in & out & stays the same size) the bursting of an animal cell when placed in a hypotonic solution. CYTOLYSIS the shrinking of a plant cell placed in a hypertonic solution. PLASMOLYSIS TURGOR PRESSURE the force that pushes out on a plant’s cell wall when it is placed into a hypotonic solution. ter a w

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 The cell is sitting in a ____________ solution. HYPERTONIC SHRINK The cell will ___________ if __________ occurs. OSMOSIS The cell is sitting in a ____________ solution. HYPOTONIC GROW The cell will ___________ if __________ occurs. OSMOSIS

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. 3. When it is really humid, doors and windows tend to stick. The higher the humidity the more water there is in the air. Explain why the doors stick? Water from the air moves into the wood of the door causing them to swell so they are harder to close.

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.

CYTOPLASMIC ORGANELLES An ORGANELLE is a tiny structure that performs a specialized function (or job) in the cell. Structure or Organelle What is the function of the organelle or structure? (What does it do? ) Is it found in Prokaryotes (Yes/No) Sketch Bacteria Nucleolus NUCLEUS Holds & protects the genetic information of the cell. Is it found in Eukaryotes… If so which ones? Plants Animals DNA NO YES Nuclear Envelope CELL MEMBRANE CELL WALL RIBOSOME Separates the cell from the outside and controls what enters and leaves the cell Provides added structure & support. Found outside the cell membrane. Location of protein production Cell Membrane YES YES YES NO YES Cell Wall

Structure or Organelle What is the function of the organelle or structure? (What does it do? ) Sketch Is it found in Prokaryotes (Yes/No) Bacteria ENDOPLASMIC RETICULUM Transport channel of proteins (E. R) GOLGI APPARTUS (BODIES) LYSOSOMES Is it found in Eukaryotes… If so which ones? Plants Animals NO YES Stacks of membranes that collect, modify, repackage & release proteins for use in or out of the cell. NO YES An organelle that contains digestive enzymes used to clean up old worn out parts of the cell (or waste). NO NO YES NO Uses energy from the sun CHLOROPLAST to make GLUCOSE. This process is called PHOTOSYNTHESIS

Structure or Organelle What is the function of the organelle or structure? (What does it do? ) Sketch Is it found in in Eukaryotes… If so which Prokaryotes ones? (Yes/No) Bacteria ATP MITOCHONDRIA Makes _______ - a usable NO form of cell energy. This process is called Plants Animals YES CELLULAR RESPIRATION Plant Cell VACUOLE Sac like structure that stores materials such as water, salts, carbs, and proteins. Vacuole NO YES (Large (Small) Central) Nucleus Framework of filaments and CYTOSKELETONfibers that supports the cell structure. YES

Structure or Organelle What is the function of the organelle or structure? (What does it do? ) Sketch Is it found in Prokaryotes Eukaryotes… If so (Yes/No) which ones? Bacteria Part of the cytoskeleton – FLAGELLUM long whip-like tail that helps with movement Plants Animals YES NO YES Part of the cytoskeleton – many small hairs that helps with movement as well NO NO YES CENTRIOLES Part of the cytoskeleton that help with cell division NO NO YES CILIA Flagellum Pathway for Proteins: proteins made at ribosome proteins travel thru E. R. Proteins modified/ sorted/shipped out of Golgi

Notes: Prokaryotic versus Eukaryotic Cells Cell Theory • All living things are made up of one or more cells • Cells are the basic unit of structure and function of an organism. • All cells come from pre-existing cells. All cells can be divided into one of two categories based upon their complexity: o. Prokaryotic Cells are very SMALL NUCLEUS Do not have a _____(the part that contains the DNA) Do not have membrane bound ORGANELLES UNICELLULAR Usually small and ________(meaning they are made up of a single cell) Example: BACTERIA

Eukaryotic Cells are LARGER Have a NUCLEUS Have membrane bound ORGANELLES Can be both unicellular and MULTICELLULAR Example: Cells of PLANTS & ANIMALS v Structures that are common to all cells are: DNA CELL MEMBRANE CYTOPLASM RIBOSOMES

Complete the table by checking the correct column for each statement: Statement Prokaryotes Eukaryotes 1. Organisms that have cells lacking internal membrane bound structures. X 2. Do not have a nucleus X 3. Can be either single-celled or made up of many cells 4. Are always single-celled organisms. 5. Organisms that have cells containing membrane bound organelles X X X

How did the first Eukaryotic cells come about?

How did the first Eukaryotic cells come about? INSIDE Endosymbiotic Theory – endo means ______________, RELATIONSHIP symbiotic means ______________ so…… PROKARYOTES – Smaller _____________ entered inside larger prokaryotes. PROTECTION – The smaller prokaryote(s) got __________________. ENERGY – The larger prokaryote got ___________________. • This smaller cell was really good at producing _______ and ATP MITOCHONDRIA came to be known as the _____________. – Eventually a 2 nd small prokaryotic cell was engulfed by the larger cell… • This cell was really good at absorbing solar energy and using it to make CHLOROPLAST food for itself and came to be known as the _________.

Support for the endosymbiotic theory: • Unlike other organelles, mitochondria & REPRODUCE chloroplasts both __________ independently of the cell. • Both mitochondria & chloroplasts contain DNA their own _____ MEMBRANES • Both have two __________around them. AUTOGENY _______________ Theory – organelles formed when the plasma membrane folded inward producing membranes inside of the cell. Some of the infolds broke off forming various organelles. Endosymbiosis Animation

Cell Specialization Type of cell Picture Function Nerve cell Long and forms chains with other nerve cells to send signals through the body Villi in the small intestine Increased surface area to absorb many nutrients Red blood cell Round to fit through blood vessels Sperm cell Has a tail (flagella) for swimming Skin cells Many layers to protect the body

Cell Specialization 1. Why are cells specialized? 1. So different cells can perform different functions. 2. What are stem cells? – 2. Cells that can become anything. They have not differentiated or become specialized yet.

Microscopes Types of Microscopes 1. Compound Light Microscope: • Uses two lenses: OBJECTIVES and OCULAR (EYEPIECE) • Used to magnify and show detail of a TRANSLUCENT specimen (one that light can pass through). • Image is INVERTED as a result of the lenses that are used. • Can magnify up to 1500 -2000 times (The ones we have only magnify up to 400 times). • The equation below is used to calculate total magnification: • Total magnification = magnification of X magnification of OBJECTIVE lens OCULAR lens – Ex: If the eyepiece magnifies the image 10 x and the low power objective magnifies the image 10 x, then the total magnification of the image would be: 10 x 10 = 100

Microscopes Continued FIELD OF VIEW - This is the visible area seen through the microscope when the specimen is in focus. • The greater the magnification, the ______ SMALLER the field of view will be. • LOW POWER MEDIUM POWER HIGH POWER 2. Stereomicroscope (also known as ____________Microscope). DISSECTING LARGE Useful when viewing objects that are too __________or too ______for the compound light microscope. THICK Unlike the compound light microscope, the images seen are not inverted. This is TWO because you are using ________eyepieces (binocular scope). Can only magnify up to _______ - _______times. 4 X – 50 X

ELECTRON MICROSCOPES SEM 3. Scanning Electron Microscopes – _______* SURFACE – Shows the ________only – Can magnify up to _____times 100, 000 4. Transmission Electron Microscope – ______* TEM INSIDE §Electrons pass through the object - allows you to “see” _______ 200, 000 §Can magnify up to ______times ** A big problem of the SEM and TEM is that the specimen must be DEAD ___________ in order to view in with one of these microscopes.