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UNIT 3 CELL BOUNDARIES AND TRANSPORT
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CELL BOUNDARIES Cell Wall – _____________ & _____________ the cell – Lies outside of the __________________ – Is made of ______________& ______________ – Plant cell walls are mainly ___________ – Fungi cell walls are mainly ___________ supportprotect cell membrane carbohydrates proteins cellulose chitin
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II. CELL Membrane A cell is defined as the smallest _________ unit of life. In order to maintain ___________, _______ must be moved into the cell and ______ must be transported out of the cell. In addition, some cells produce _________ and other materials designated for export. All materials moving in and out of the cell must pass through the ____________a ______________boundary found in ____ cells. CELL BOUNDARIES working homeostasisnutrients wastes hormones cell membrane semi permeable all
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Cell Membrane in a Nutshell (187-190) – Made mainly of ____________ & _________ – Hydrophobic tails of phospholipids make molecules line up as a _______ with polar head facing _____ and nonpolar tails facing ___. phospholipid proteins bilayer out in
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Function – Membranes are __________________ = Semi- permeable, picky – Allow certain molecules to pass through; but keeps others out – __________ what enters & leaves the cell – Helps maintain ___________ selectively permeable Controls homeostasis
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Other components of the cell membrane – Proteins- Peripheral- on the inside or outside surface – Receptor proteins- on the outside surface; ________________ to inside cell – On inside surface; __________ the cell membrane to cell’s internal support structure (cytoskeletal) giving cell its shape – Transport proteins (also called integral)- _______________________ through the membrane; used as channels or tunnels to move things in or out of the cell transmit signals anchors embedded all the way
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Other components of the cell membrane Cholesterol- only in _______ cells – Helps prevent fatty acid tails from ________ together – Provides ________ for ________ cell (no cell wall) animal sticking stabilityanimal
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Other components of the cell membrane Carbohydrates- in chain form; on outside surface – Used to ____________ ; cell ID tags – If found on top of a protein the whole structure is called a _____________ – If found on top of a phospholipid the whole structure is called a _________ recognize self glycoprotein glycolipid
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Label the following cell membrane 1.Transport/Integral Protein 2.Peripheral Protein on the inside 3.Glycoprotein 4.Glycolipid 5.Cholesterol
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CARBOHYDRATES On the outside of the cell membrane to identify as “self or non-self”
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PROTEINS Embedded in the bilayer Serve as channels & pumps for transport of specific molecules across the cell membrane
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What biomolecule regulates what can enter or leave the cell w/o a channel or pump? A.Lipid B.Carbohydrate C.Protein D.Nucleic Acid
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What biomolecule Serve as channels & pumps for transport A.Lipid B.Carbohydrate C.Protein D.Nucleic Acid
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What biomolecule is used to to identify as “self or non-self” A.Lipid B.Carbohydrate C.Protein D.Nucleic Acid
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Non-polar, middle portion of cell membrane A.a B.b C.c D.d E.e
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Embedded in cell membrane, serve as channels & pumps A.a B.b C.c D.d E.e
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Polar portion of cell membrane oriented towards water A.a B.b C.c D.d E.e
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Provides stability for animal cell membrane A.a B.b C.c D.d E.e
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Serve as “id” tags for cell A.a B.b C.c D.d E.e
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CELL TRANSPORT Passive Transport Does NOT require ________ Movement of substances from a ______ concentration to ______ 3 Types: o Diffusion o Facilitated diffusion o Osmosis energy high low
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DIFFUSION Diffusion: Random movement of molecules in a ________ or _____ Many substances move across the ________________ by diffusion, for example _________________________ Example: odor gradually fills a room cell membrane water, oxygen, & small molecules liquid gas
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FACILITATED DIFFUSION Facilitated Diffusion: Diffusion of _____________through a _____________ Ex: glucose as it is transported across a cell membrane by a protein channel large molecules protein channel
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FACILITATED DIFFUSION Protein channels provide larger openings for larger molecules like ________________. In addition, due to the _________ fatty acid tails that make up most of the phospholipid bilayer, _____ molecules and _____ utilize protein channels. glucose, & fructose non-polar polar ions
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FACILITATED DIFFUSION This includes ________, which utilizes specialized protein channels known as ________________. ***A protein pump is active transport so this sentence should be in the active transport section Na & K Protein pumps
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OSMOSIS Osmosis: Diffusion of ________from a _______ water concentration to a ________ water concentration through a __________________ membrane. There are comparative terms used to describe the water versus solute concentration on either side of the a membrane: waterhigh low Selectively permeable
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OSMOSIS Hypertonic = __________________solute; _________________water Hypotonic = ____________________solute; _________________water – Water always moves from ___________→ ______________ higher concentration lower concentration higher concentration hypOtonic hyp er tonic
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OSMOSIS Isotonic = Relative concentrations of ______ and ______ are ________ – There will be ___ net movement of water if two solutions are isotonic water solute equal no
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OSMOSIS Cells must have a mechanism for counteracting the pressure osmosis can create, otherwise a cell could swell & burst or explode when it is placed in a ___________ environment How to control Osmotic Pressure: o Cell wall - Rigid boundary found in ________________ o Physically prevents cell from expanding o Contractile vacuole- Actively________ water out of cell single-celled organisms without ________ o Blood/Extracellular Fluid- is mostly water to equalize osmotic pressure. Designed to be __________ with cells. hypotonic pumps Cell walls Plants, bacteria, fungi & some protists isotonic
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-Hypotonic; -cell will undergo cytolysis or lyse (the cell will burst) -This is kills the animal cell -Hypertonic; -cell will crenate (the cell will shrivel up) -This causes cell to dehydrate and not function -isotonic; -preferred cell state -Hypertonic; -cell will undergo plasmolysis (cell membrane pulls away from cell wall) -isotonic; -Cell does not mind being in this state; neither beneficial or harmful to the cell -Hypotonic; -cells see increased turgor pressure -This is the preferred state for plant cells
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ACTIVE TRANSPORT Requires energy in the form of ATP 3 types: Protein Pumps Endocytosis Exocytosis
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PROTEIN PUMPS Protein Pumps: 1. Protein Pumps – Energy-requiring process during which membrane proteins pump molecules across a membrane ____________________ from a ______ concentration to a ________concentration. concentration gradient low high
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PROTEIN PUMPS An example is the sodium-potassium pump. Its purpose is to establish an _____________ gradient in cells by pumping __ sodium ions (__) out of the cell for every __ potassium ions (__) pumped into the cell. This slight ________ charge inside the cell relative to the outside is very important for ________________ and _________________. electrochemical 3 Na 2 K negative muscle contractions Nerve impulses
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ENDOCYTOSIS AND EXOCYTOSIS Endocytosis: “cell eating or sucking”. Larger substances are moved into the cell from the exterior by extending the cell membrane, forming a vesicle around the substance. Examples include macrophages, amoeba, etc. Exocytosis- “cell spitting ”. Export of molecules from the inside of the cell to the exterior of the cell by a vesicle fusing with the cell membrane. Mechanism used to release hormones from cells
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ENDOCYTOSIS AND EXOCYTOSIS
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Random movement of molecules in a liquid or gas A.Active transport B.Diffusion C.Endocytosis D.Exocytosis E.Facilitated Diffusion F.Osmosis G.Passive Transport H.Protein Pump
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Requires energy in the form of ATP A.Active transport B.Diffusion C.Endocytosis D.Exocytosis E.Facilitated Diffusion F.Osmosis G.Passive Transport H.Protein Pump
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cell sucking in or eating A.Active transport B.Diffusion C.Endocytosis D.Exocytosis E.Facilitated Diffusion F.Osmosis G.Passive Transport H.Protein Pump
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Diffusion of specific molecules through a protein channel A.Active transport B.Diffusion C.Endocytosis D.Exocytosis E.Facilitated Diffusion F.Osmosis G.Passive Transport H.Protein Pump
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Diffusion of water through a selectively permeable membrane A.Active transport B.Diffusion C.Endocytosis D.Exocytosis E.Facilitated Diffusion F.Osmosis G.Passive Transport H.Protein Pump
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Movement of molecules from high concentration to low, does NOT require energy A.Active transport B.Diffusion C.Endocytosis D.Exocytosis E.Facilitated Diffusion F.Osmosis G.Passive Transport H.Protein Pump
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Movement of ions and molecules against the concentration gradient, requires energy A.Active transport B.Diffusion C.Endocytosis D.Exocytosis E.Facilitated Diffusion F.Osmosis G.Passive Transport H.Protein Pump
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Cell spitting out or pooping A.Active transport B.Diffusion C.Endocytosis D.Exocytosis E.Facilitated Diffusion F.Osmosis G.Passive Transport H.Protein Pump
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