BIOL 101 Guided Reading Questions GRQs Complete and submit this GRQ as a PDF before lecture and before your online Mastering Assignment L3 GRQs A Tour of the Cell Reading Objectives Describe properties of all cells relative to surface area structural components and function Differentiate bacteria plant and animal cell structures Describe the structure and function of eukaryotic cell components Explain how proteins are secreted from a eukaryotic cell Describe how diabetes occurs and how cell signaling is involved Module 4 2 The small size of cells relates to the need to exchange materials across the plasma membrane 1 Why can t cells get very big Cells cannot get very big because the maximum size of a cell is influenced by geometry meaning that the cell needs to have a surface area large enough to service the volume of a cell 2 As cell size increases what happens to its surface to volume ratio As the size of a cell increases the surface to volume ratio decreases 3 What is the structure and function of the plasma membrane The plasma membrane structure is composed of an extremely thin flexible boundary between the living cell and its surrounding environment separating life from nonlife The function of the plasma membrane serves as a selective barrier to the passage of ions and molecules in and out of the cell Modules 4 3 4 4 Prokaryotic cells are structurally simpler than eukaryotic cells Eukaryotic cells are partitioned into functional compartments 1 There are two kinds of cells in nature 2 All cells have some features in common list them define any you aren t familiar with Prokaryotic Eukaryotic a b Plasma membrane Cytosol Chromosomes Ribosomes Cytoplasm DNA 3 Draw figure 4 3 a bacterium for yourself Label and be sure to define each part Take note of what a prokaryotic cell contains so that you can easily see what it is missing compared to a eukaryotic cell 4 Compare and contrast eukaryotic and prokaryotic cells Prokaryotic cells differentiate from eukaryotic cells in that they are only found in bacteria and archaea they are much smaller and simpler in structure they lack a membrane enclosed nucleus DNA is coiled into nucleoid rather than surrounded by membrane and do not have membrane enclosed organelles On the other hand eukaryotic cells contain membrane enclosed organelles as well as a membrane enclosed nucleus 5 What is the advantage for the cell in having compartments within a eukaryotic cell The advantage of having compartments within a eukaryotic cell is that each compartment specializes in a specific metabolic function Therefore making it possible for the cell to carry out more than one process simultaneously 6 Compare and contrast a plant cell and an animal cell Examine diagrams of typical organelles of plant and animal cells what differences do you see Plant cells contain chloroplasts cell walls and central vacuoles Whereas animal cells contain centrosomes and lysosomes However they both have smooth and rough ER plasma membrane golgia apparatus mitochondria cytoskeleton ribosomes and a nucleus Modules 4 5 4 6 The nucleus contains the cell s genetic insrtuctions Ribosomes make protesin for use in the cell and for export 1 Name and sketch the structure that matches the functional description of each component a The cell s genetic instructions inside the nucleus DNA b A barrier separating the cell s genetic information from the cell s cytosol Nuclear envelope c How materials enter and exit the nucleus Proteins made by ribosomes 2 DNA is transcribed into another set of instructions called Messenger RNA mRNA that directs protein synthesis 3 A cell with many ribosomes structural characteristic tells you what about this cell s function A cell with many ribosomes creates a lot of proteins 4 What is the difference between proteins that are made by free ribosomes in the cytosol or ribosomes attached to the endoplasmic reticulum or nuclear envelope Proteins that are made by free ribosomes in the cytosol function within the cytosol and proteins made by ribosomes attached to the ER or nuclear envelope will be inserted into membranes packaged in certain organelles or exported from the cell Modules 4 8 4 10 4 12 The endoplasmic reticulum is a biosynthetic workshop The Golgi apparatus modifies sorts and ships cell products Lysosomes are digestive compartments within a cell A review of the structures involved in manufacturing and breakdown 1 The rough ER and Golgi form a functional unit that help to produce what for the cell Describe this process Drawing will help you work through biological processes The golgi receives transport vesicles budded from the rough ER that contain proteins synthesized by bound ribosomes The golgi finishes processing and dispatches transport vesicles to the plasma membrane where the proteins are then excreted 2 What is the function of lysosomes Lysosomes are membrane enclosed sacs of digestive enzymes that help to disgust engulfed food or damaged organelles destroy bacteria and are used as recycling centers 3 What is one disease associated with malfunction of the lysosomal enzymes Lysosomal storage disease is associated with the malfunctioning of lysosomal enzymes Modules 4 13 4 15 Mitochondria harvest chemical energy from food Chloroplasts convert solar energy to chemical energy Mitochondria and chloroplasts evolved by endosymbiosis 1 What is the function of mitochondria Do prokaryotes animal cells or plant cells have mitochondria Mitochondria are organelles that carry out cellular respiration and ATP is made Almost all eukaryotes contain mitochondria including both plant and animal cells 2 What is the function of chloroplasts Do prokaryotes animal cells or plant cells have chloroplasts Chloroplasts are the photosynthesizing organelles of plants and algae they absorb sunlight and use it to drive the synthesis of organic compounds from carbon dioxide and water Only eukaryotic plant cells contain chloroplasts 3 Draw pictures of a mitochondrion and a chloroplast as the structures of these become very important to our discussion of cellular respiration and photosynthesis What are the names of each compartment space Be sure they are labeled on your pictures 4 All eukaryotes have mitochondria but not all eukaryotes have chloroplasts Can you propose an evolutionary explanation for this observation The first endosymbiosis would have given rise to eukaryotic cells containing mitochondria Second endosymbiotic event gave rise to cells containing chloroplasts as well as
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