Bio Chapter 5

Chapter 5 Test Study Guide

The Working Cell

This is a brief overview of the topics we covered in Chapter Five, not a comprehensive guide for the Test. You should review this as well as your notes, worksheets, labs, review games, etc.

Big Ideas: 

1. A cell membrane’s structure enables its many functions, such as regulating traffic across the membrane. 

2. A cell’s metabolic reactions transform energy, using ATP to drive cellular work. 

3. Enzymes speed up a cell’s chemical reactions and provide precise control of metabolism. 

5.1 Membranes are fluid mosaics of lipids and proteins with many functions

• What is the Fluid mosaic model? 

  • Why is the plasma membrane called that?

  • What does selective permeability mean?

  • What are the types of proteins/molecules found within the plasma membrane 

    • Transport proteins - allows specific ions or molecules to enter and leave the cell

    • Enzymes - grouped to carry out sequential chemical reactions, only the reactant and the substrate can go through

    • Attachment Proteins - attached to the extracellular matrix and cytoskeleton, helps to support the membrane, coordinates external and internal changes

    • Receptor Proteins - signal molecules bind to receptor proteins, relay information by activating other molecules in the cell

    • Junction Proteins - form junctions between two cells to attach them

    • Glycoproteins - act as an ID tag, could be recognized by other membrane proteins on other cells

      • Image pg 87

5.3 Passive transport is diffusion across a membrane with no energy investment

• Define passive transport.

  • What is diffusion?

    • Know word problems

• What is a concentration gradient?

  • What direction do molecules move?

5.4 Osmosis is the diffusion of water across a membrane

• Define osmosis

  • How does water move in relation to other solutes?

    • Know word problems

  • What is the transport protein that allows water to pass through?

5.5 Water balance between cells and their surroundings is crucial to organisms

• What is tonicity?  

  • Know the difference between isotonic, hypertonic, and hypotonic

  • What examples of each

  • Be familiar with what happens to cells that are placed in those solutions

    • Image pg 81

5.6 Transport proteins can facilitate diffusion across membranes

• What is facilitated diffusion?

• How is it different from diffusion?

  • Know word problems

5.8 Cells expand energy in the active transport of a solute 

• What is active transport?

• Be familiar with the Na/K pump mechanisms 

5.9 Exocytosis and endocytosis transport large molecules across membranes 

• What is exocytosis? What is endocytosis?

  • Compare and contrast

  • Know examples of each

5.10 Cells transform energy and matter as they perform work

• What are the different forms of energy?

• How is energy transformed?

  • Know the 1st law of thermodynamics

    • Image pg 84

5.11 Chemical reactions either release or store energy 

• What are exergonic and endergonic reactions?

  • How do they use energy?

  • Know examples of each

5.12 ATP drives cellular work by coupling exergonic and endergonic reactions 

• What is ATP?

  • Know the chemical structure 

  • Compare and contrast ADP and ATP

• How do we use ATP?

  • Know examples of different cellular work powered by ATP

5.13 Enzymes speed up the cells’ chemical reaction by lowering energy barriers 

• What is a catalyst?

• What is an enzyme?

  • How do they do the work? 

5.14 A specific enzyme catalyzes each reaction

• What is the catalytic cycle of an enzyme?

  • How is the shape of an enzyme related to its function?

• What are the optimal conditions for enzymes?

5.15 Enzymes inhibition can regulate enzyme activity in a cell

• Compare and contrast competitive, noncompetitive and feedback inhibition

5.16 Many drugs, pesticides and poisons are enzyme inhibitors

• Know some examples