Transport and Energy

Transport and Energy

Chapter 5

Transport and Energy

Chapter 5 Objectives

Opening Essay

Explain how organisms use bioluminescence to attract mates or prey, repulse predators, or communicate.

Membrane Structure and Function

5.1Describe the fluid mosaic structure of cell membranes.

5.1Describe the diverse functions of membrane proteins.

5.1Relate the structure of phospholipid molecules to the structure and properties of cell membranes.

5.2Explain how the properties of phospholipids spontaneously form membranes.

5.3Define diffusion and describe the process of passive transport.

5.4Explain how osmosis can be defined as the diffusion of water across a membrane.

5.5Distinguish between hypertonic, hypotonic, and isotonic solutions.

5.5Explain how animal and plants cells change when placed into hypertonic or hypotonic solutions.

5.6Explain how transport proteins facilitate diffusion.

5.6–5.8Compare the processes of facilitated diffusion and active transport.

5.7Describe the function of aquaporins in cell membranes.

5.9Distinguish between exocytosis, endocytosis, phagocytosis, pinocytosis, and receptor-mediated endocytosis.

Energy and the Cell

5.10Define and compare kinetic energy, potential energy, chemical energy, and heat.

5.11Define the first and second laws of thermodynamics. Explain how these laws of thermodynamics relate to energy use in a cell.

5.12Define and compare endergonic and exergonic reactions. Explain how cells use cellular respiration and energy coupling to survive.

5.13Describe the three main types of cellular work.

5.13Explain how ATP functions as an energy shuttle.

How Enzymes Function

5.14Explain how enzymes speed up chemical reactions.

5.15Describe the structure of an enzyme-substrate interaction.

5.15Explain how the cellular environment affects enzyme activity.

5.16Explain how competitive and noncompetitive inhibitors alter an enzyme’s activity.

5.16Explain how certain poisons, pesticides, and drugs inhibit enzymes.

5.16Describe the process of feedback inhibition.

Key Terms

active site

active transport

adenosine triphosphate (ATP)

aquaporin

cellular respiration

chemical energy

coenzyme

cofactor

competitive inhibitor

concentration gradient

diffusion

endergonic reaction

endocytosis

energy coupling

energy of activation (EA)

energy

entropy

enzyme

exergonic reaction

exocytosis

facilitated diffusion

feedback inhibition

first law of thermodynamics

fluid mosaic

heat

hypertonic solution

hypotonic solution

induced fit

isotonic solution

kinetic energy

metabolic pathway

metabolism

noncompetitive inhibitor

osmoregulation

osmosis

passive transport

phagocytosis

phosphorylation

pinocytosis

potential energy

receptor-mediated endocytosis

second law of thermodynamics

selective permeability

substrate

thermodynamics

tonicity

Word Roots

aqua- 5 water; -pori 5 a small opening (aquaporin: a transport protein in the plasma membrane of a plant or animal cell that facilitates the diffusion of water across the membrane)

co- 5 together (cofactor: a nonprotein molecule or ion that is required for the proper functioning of an enzyme)

endo- 5 inner, within (endergonic reaction: an energy-requiring chemical reaction that yields products with more potential energy than the reactants); cyto- 5 cell (endocytosis: cellular uptake of molecules or particles via formation of new vesicles from the plasma membrane)

exo- 5 outer (exergonic reaction: an energy-releasing chemical reaction in which the reactants contain more potential energy than the products; exocytosis: the movement of materials out of the cytoplasm of a cell by the fusion of vesicles with the plasma membrane)

hyper- 5 exceeding; -tonus 5 tension (hypertonic: a solution with a higher concentration of solutes)

hypo- 5 lower (hypotonic: a solution with a lower concentration of solutes)

iso- 5 same (isotonic: solutions with equal concentrations of solutes)

kinet- 5 movement (kinetic energy: the energy of motion)

osmo- 5 pushing (osmosis: the diffusion of water across a selectively permeable membrane)

phago- 5 eat (phagocytosis: cellular “eating,” a type of endocytosis in which a cell engulfs macromolecules, other cells, or particles into its cytoplasm)

pino- 5 drink (pinocytosis: cellular “drinking,” a type of endocytosis in which the cell takes fluid and dissolved solutes into small membranous vesicles)

therm- 5 heat (thermodynamics: the study of the energy transformations that occur in a collection ofmatter)

Student Media

Membrane Structure and Function

Activity: Membrane Structure (5.1)

Activity: Signal Transduction (5.1)

Activity: Selective Permeability of Membranes (5.1)

Activity: Diffusion (5.3)

Activity: Osmosis and Water Balance in Cells (5.5)

Activity: Faciliated Diffusion (5.6)

Activity: Active Transport (5.8)

Activity: Exocytosis and Endocytosis (5.9)

Process of Science: How Do Cells Communicate with Each Other? (5.1)

Process of Science: How Does Osmosis Affect Cells? (5.5)

Video: Plasmolysis (5.5)

Video: Turgid Elodea (5.5)

Video: Chlamydomonas (5.5)

BLAST Animation: Diffusion (5.3)

BLAST Animation: Passive Diffusion Across a Membrane (5.3)

BLAST Animation: Active Transport (5.8)

BLAST Animation: Endocytosis and Exocytosis (5.9)

Energy and the Cell

MP3 Tutor: Basic Energy Concepts (5.10)

Activity: Energy Transformations (5.10)

Activity: Chemical Reactions and ATP (5.12)

Activity: The Structure of ATP (5.13)

BLAST Animation: ATP/ADP Cycle (5.13)

BLAST Animation: Structure of ATP (5.13)

How Enzymes Function

Activity: How Enzymes Function (5.15)

Process of Science: How is the Rate of Enzyme Catalysis Measured? (5.15)

BLAST Animation: Enzymes: Activation Energy (5.14)

BLAST Animation: Enzymes: Types and Specificity (5.15)

BLAST Animation: Enzyme Regulation: Competitive Inhibition (5.16)

BLAST Animation: Enzyme Regulation: Chemical Modification (5.16)