Unit 4 Guide: Cells and Cell Transport (PDF)

Unit 4 Guide: Cells and Cell Transport Topics: prokaryotes and eukaryotes, plant and animal cells, organelles and functions, cellular membrane structure and function, active transport, passive transport Key Terms: Cell theory Golgi apparatus Pas...

Unit 4 Guide: Cells and Cell Transport Topics: prokaryotes and eukaryotes, plant and animal cells, organelles and functions, cellular membrane structure and function, active transport, passive transport Key Terms: Cell theory Golgi apparatus Passive transport Eukaryote Vesicles Diffusion Prokaryote Ribosomes Facilitated diffusion Bacteria Cell wall Osmosis Archaea Centrioles Hypertonic Protists Endoplasmic reticulum Hypotonic Plant cell Chloroplast Isotonic Animal cell Plastid Sodium-potassium pump Fungi Cytoplasm Endocytosis Cell membrane Phospholipid bilayer Exocytosis Mitochondria Fluid Mosaic Model Aquaporins Lysosomes Selectively permeable Neuron Nucleus Concentration gradient Action potential Nucleolus Active transport Objectives: ​ Be able to explain the principles of cell theory and its significance in the field of biology ​ Be able to differentiate between prokaryotic and eukaryotic cells, and explain their structural and functional differences ​ Be able to label typical prokaryotic and typical eukaryotic cell structures ​ Be able to describe the key characteristics of bacteria and archaea ​ Be able to identify and classify various eukaryotic cell types, including protists, plant cells, animal cells, and fungi, based on their unique features ​ Be able to differentiate between plant and animal cells ​ Be able to label typical animal and typical plant cell structures ​ Be able to identify, label, and state the function of organelles ​ Be able to label and describe the Fluid-Mosaic Model of the cell membrane. ​ Be able to define passive transport and its role in the movement of substances across cell membranes. ​ Be able to explain the processes of diffusion and facilitated diffusion and provide examples of each. ​ Be able to describe the concept of osmosis and its effects on cells in hypertonic, hypotonic, and isotonic solutions.  ​ Be able to explain and compare hypertonic, hypotonic, and isotonic solutions. ​ Be able to discuss the role of aquaporins in facilitating the movement of water across cell membranes. ​ Be able to distinguish between active and passive transport and what is causing the movement of materials in both types of transport. ​ Be able to explain the structure and function of neurons, emphasizing their role in transmitting electrical signals in the nervous system. Review/Guiding Questions: 1.​ Explain the principles of cell theory and why it is significant in the field of biology. 2.​ What is the difference between prokaryotic and eukaryotic cells? What are their structural and functional differences? 3.​ Draw and label a typical prokaryotic cell structure. 4.​ Draw and label a typical eukaryotic cell structure. 5.​ Describe the key characteristics of bacteria and archaea. 6.​ Identify defining characteristics of various eukaryotic cell types: protists, plants, animals, and fungi. 7.​ Explain the differences between plant and animal cells. 8.​ Identify and label a typical animal cell structure. 9.​ Identify and label a typical plant cell structure. 10.​Identify the structures and functions of cell organelles. 11.​Describe the Fluid-Mosaic Model of the cell membrane and label its key components. 12.​Define passive transport and explain its role in the movement of substances across cell membranes. 13.​Explain the process of diffusion and provide an example. 14.​Explain the process of facilitated diffusion and provide an example. 15.​Describe the concept of osmosis and its effects on cells in hypertonic, hypotonic, and isotonic solutions. 16.​Explain the differences between hypertonic, hypotonic, and isotonic solutions. 17.​Compare and contrast endo- and exocytosis. 18.​What drives the process of active transport? 19.​Compare and contrast passive and active transport. 20.​Discuss the role of aquaporins in facilitating the movement of water across cell membranes. 21.​Explain the structure and function of neurons Unit 4 Videos & Application Questions Videos 1.​ Amoeba Sisters Introduction to the Cell: https://youtu.be/8IlzKri08kk?feature=shared  2.​ Amoeba Sisters Prokaryotes vs Eukaryotes: https://youtu.be/Pxujitlv8wc?feature=shared 3.​ Crash Course Biology Eukaryopolis: https://youtu.be/cj8dDTHGJBY?feature=shared 4.​ Crash Course Biology Plant Cells: https://youtu.be/9UvlqAVCoqY?feature=shared 5.​ Amoeba Sisters Inside the Plasma Membrane https://tinyurl.com/bzbwxdrs 6.​ Amoeba Sisters Diffusion https://tinyurl.com/y2djyjk3 7.​ Amoeba Sisters Osmosis and Water Potential https://youtu.be/L-osEc07vMs?feature=shared 8.​ Crash Course Biology Membranes and Transport https://youtu.be/dPKvHrD1eS4?feature=shared Application Questions Use the graph below to answer questions 1-4. 1.​ Given the information in the graph, which type of cell transport would be best to move substances into or out of the cell quickly? 2.​ Which type of transport would be the best if the cell needs to respond to a sudden concentration gradient difference? 3.​ Why would the line representing facilitated diffusion level off as the concentration gets higher, while the line representing diffusion continues to go up at a steady rate? 4.​ Why does active transport, on the same graph, start off with such a high initial rate compared to diffusion and facilitated diffusion? 5.​ Using the concept of osmosis, explain why water is sprayed over produce in a grocery store. How might this change the appearance of the produce, and why would this change be desirable? 6.​ Suppose you made a lettuce salad in the afternoon, added salt and other seasonings, and then put the salad in the refrigerator. When you took the salad out of the refrigerator for dinner, the lettuce looked wilted and some water was in the bottom of the bowl. Use the principles of osmosis to explain what happened. 7.​ In extreme cases, it is possible to die from drinking too much water. The consumption of several liters of water in a short amount of time can lead to brain edema (swelling) and death. Explain the effect of ingesting an extremely large amount of water at the level of the brain cells, including the role of osmosis in this process. Cells and Cell Transport 1.​ Cells a.​ Definition Smallest basic unit of life that is responsible for all of life's processes. Every living thing is composed of 1 or more cells. Even single celled organisms meet 8 characteristics of life. b.​ Discovery i.​ Main scientists and their contributions (NEED TO KNOW FOR TEST)​ Anton van leeuwenhoek - found bacteria/ ‘animalcules’/ blood cells Robert hooke- invented/coined the term ‘cell’ 1600’s Matthias schleiden - discovered that all plants were made of cells 1838 Theodore schwann- discovered that all animals were made of cells 1839 Rudolph virchow - stole robert remacks work on cell division 1858 Robert remak - discovered cell division, completing cell theory 1852 c.​ Cell Theory i.​ 3 parts of cell theory -​ All organisms are composed of cells -​ All cells come from preexisting cells -​ Cells are the basic unit of life 2.​ Cell Diversity  a.​ All cells have 4 basic structures in common - cell membrane (phospholipid bilayer), cytoplasm, ribosomes, genetic material (DNA, RNA) b.​ Prokaryotes i.​ Description No nucleus No membrane- bound organelles unicellular organisms Smaller than eukaryotes c.​ Eukaryotes i.​ Description Nucleus Have membrane bound organelles Usually part of multicellular organisms, but can be unicellular, like yeast or algae Usually larger than prokaryotic cells. 3.​ Prokaryotes a.​ Defining characteristics b.​ Subclass = bacteria i.​ Description Cell walls have peptidoglycan (peptidoglycan is a sugar) kinda like what cellulose is to plant walls Autotroph or heterotroph Large portion of all living things ii.​ Examples c.​ Subclass = archaea i.​ Description No peptidoglycan in cell walls Autotroph or heterotroph Extremophiles (found in very extreme environments where not many other life forms can survive) Have distinct genes and metabolic pathways that are totally different from bacteria (the way they make and store energy is totally different) ii.​ Examples 4.​ Eukaryotes a.​ Defining characteristics  b.​ Subclass = protista i.​ Description Some have cells walls of cellulose Come have chloroplasts Lots of unicellular Some multicellular organisms Some colonial (colonial organisms are individual cells that require being together to live and function together) Some are autotrophs, some are heterotrophs ii.​ Examples Slime mold amoeba c.​ Subclass = fungi i.​ Description Cell walls made of chitin (found in exoskeleton of insects) Mostly multicellular Heterotrophic (secrete digestive enzymes onto food source, like decaying animals or plants) ii.​ Examples Mushrooms d.​ Subclass = planate i.​ Description Cell walls with cellulose Chloroplasts Multicellular autotrophic ii.​ Examples Trees, grass, ferns e.​ Subclass = animalia i.​ Description Us! No cell walls No chloroplasts Multicellular heterotroph ii.​ Examples Humans, insects, mammals, birds, fish Organelles unique to animal cells: centrioles Lysosomes Multiple vacuoles Sodium potassium pump Organelles unique to plant cells: chloroplasts Cell walls Central vacuole 5.​ Cell Membrane Structure a.​ Phospholipid Bilayer (structure that makes up membrane) i.​ Description Thin flexible boundary between a cell and its surrounding environment. Exhibits selective permeability (lets some things in but not others) Fluid mosaic model - have many moving parts: phospholipid bilayer has hydrophilic heads of tails facing exterior and interior of the cell, and hydrophobic ends of tails arranged end to end on the interior (creates a boundary). ii.​ How structure fits function b.​ Cholesterol within the tails i.​ Description located within the membrane among the tails, keeps the tails from sticking together, so the cell stays flexible (flexibility allows for cells to flex and fit through capillaries etc). Too much “bad cholesterol” blocks arteries and makes cells less flexible. ii.​ Function c.​ Peripheral Proteins i.​ Description Loosely bound to membrane surface (not deeply imbedded), diverse roll: can be an anchor, intra or extracellular communication, structural support ii.​ Function d.​ Transport Protein i.​ Description: tunnel like proteins that span the entire length of phospholipid bilayer. Allow for transport of larger molecules. ii.​ Function: helps specific molecules pass back and forth across the membrane. Like a tunnel thru membrane. Include aquaporins as channel proteins. e.​ Integral Proteins i.​ Description  A protein which spans the entire width of membrane/ many in this category. Include alpha helix and transport proteins. More of a category. ii.​ Function include cell communication and channelling transport. Facilitated diffusion. Might have a carb chain attached to help with signaling. f.​ Glycolipids and Glycoproteins i.​ Description membrane carbs (glycogen) covalently bonded to proteins or lipids (glycogen is how the body stores glucose) ii.​ Function used for cell-to-cell recognition, act as receptors. g.​ Selective Permeability i.​ Description allows for some things to pass through, while blocking others. ii.​ Significance for living organisms - some things allowed in, lets the cell do it's specific job. 6.​ Cell Transport: Passive a.​ Description type of transport that does not require use of energy, regulated by cell membrane, maintains homeostasis b.​ Diffusion i.​ Description natural movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached, ii.​ Other info spray perfume, it's highly concentrated, but as it moves across the room, it becomes less concentrated until they’re equally spaced. This happens in your cells as well. You go down the concentration gradient. c.​ Facilitated diffusion i.​ Description- helper proteins are involved in the diffusion (simple diffusion ^ has no helper proteins). ii.​ Channel proteins 1.​ More details iii.​ Carrier proteins 1.​ More details - conformational change to allow diffusion. d.​ Osmosis i.​ Description- diffusion of WATER molecules specifically. ii.​ Other info - the water molecules pass through specialized proteins called AQUAPORINS. (Aquaporins are channel proteins, not carriers.)  iii.​ Solution descriptions: (have to include 2 solutions bc they are terms of comparison.) 1.​ Hypertonic- solution outside the cell has higher concentration of solute than inside the cell. (more water inside cell than outside, can’t do reactions (cell will shrivel in a hypertonic solution)) plant cells wilt, and cell membrane pulls away from the cell wall 2.​ Isotonic- solution outside the cell has equal concentration of solute than inside the cell. (ideal for us, maintain dynamic equilibrium where water moves in and out) 3.​ Hypotonic- solution outside the cell has lower concentration of solute than inside the cell. (less water inside cell than outside (cells will swell in a hypotonic environment)) cells could lyse (burst). This does not occur in plant cells, because they have a protective cell wall. 7.​ Cell Transport: Active a.​ Description atp is needed for active transport. Moving against concentration gradient (low to high, like shoving stuff in your closet and trying to close the door) b.​ Protein pumps i.​ Description special transport proteins that pump ions from low to high concentration. Need energy from ATP to induce conformational change to translocated solute across membranes. ii.​ Sodium/Potassium Pump- critical for existence, how neurons work, and send electrical signals. atp binds to the pump, is broken down and the phosphate group is broken down. iii.​ Does this by changing concentrations of sodium and potassium ions inside the cell. Sodium binds to the pump, needs to phosphorylate sodium, induces shape change, (look at diagram ) builds up sodium outside the cell, 2 potassium ions will trigger release of phosphate group, causes protein to revert back to original shape, potassium is pushed into cell. Basically wants to pump sodium out and pump potassium in.Importance for neurons ^ neuron has a long axon (tail) around chunks of tail is a myelin sheath, used for insulation of electrical signals and control of direction of electric signal. Node of ranvier, builds up positive. 3 sodium into the pump- phosphate group from atp, allows for confirmation change, shape of pump changes, releases sodium into extracellular environment. Once released, 2 potassium ions bind to it, triggers release of phosphate group, causes the cell to revert back to original  shape, and lets potassium inside. Inside every animal cell. Builds electrochemical gradients for sending electrical charge/ signal. c.​ Endocytosis i.​ Description - process of taking material into a cell by forming a vesicle form cell membrane. Cell membrane reaches around to capture particles outside the cell. ii.​ Phagocytosis - “cell eating” engulfs solid particles and brings them in. This is how amoebas eat and move. “Pseudopods” = false foot. iii.​ Pinocytosis- “cell drinking” absorbs liquid instead of solids. Difference between the 2 is that phagocytosis extends outwards, and pinocytosis opens into/ inside the cell. d.​ Exocytosis i.​ Description - taking a vesicle of stuff and fusing it to membrane to get rid of it. ii.​ More details- the vesicle is sorted based on its contents. Digestive enzymes in lysosomes will break down carbs, waste. If it's lipids, the cell will build it back into itself. Vacuole or vesicle of products or wastes fuses with cell membrane and releases contents outside cell. Golgi is involved because it is a shipping center. Vesicles produced by golgi or rough er fuse to membrane and release new phospholipids to membrane. Stuff is released for the body, some hormones are proteins or lipids, so in order for signals to be sent, they need to be released from the cell. Think exit.