Ch.7 - The MembraneSee all chapters
All Chapters
Ch.1 - Introduction to Biology
Ch.2 - Chemistry
Ch.3 - Water
Ch.4 - Carbon
Ch.5 - Biological Molecules
Ch.6 - Cells
Ch.7 - The Membrane
Ch.8 - Energy and Metabolism
Ch.9 - Respiration
Ch.10 - Photosynthesis
Ch.11 - Cell Signaling
Ch.12 - Cell Division
Ch.13 - Meiosis
Ch.14 - Mendelian Genetics
Ch.15 - Chromosomal Theory of Inheritance
Ch.16 - DNA Synthesis
Ch.17 - Gene Expression
Ch.18 - Regulation of Expression
Ch.19 - Viruses
Ch.20 - Biotechnology
Ch.21 - Genomics
Ch.22 - Development
Ch.23 - Evolution by Natural Selection
Ch.24 - Evolution of Populations
Ch.25 - Speciation
Ch.26 - History of Life on Earth
Ch.27 - Phylogeny
Ch.28 - Prokaryotes
Ch.29 - Protists
Ch.30 - Plants
Ch.31 - Fungi
Ch.32 - Overview of Animals
Ch.33 - Invertebrates
Ch.34 - Vertebrates
Ch.35 - Plant Anatomy
Ch.36 - Vascular Plant Transport
Ch.37 - Soil
Ch.38 - Plant Reproduction
Ch.39 - Plant Sensation and Response
Ch.40 - Animal Form and Function
Ch.41 - Digestive System
Ch.42 - Circulatory System
Ch.43 - Immune System
Ch.44 - Osmoregulation and Excretion
Ch.45 - Endocrine System
Ch.46 - Animal Reproduction
Ch.47 - Nervous System
Ch.48 - Sensory Systems
Ch.49 - Muscle Systems
Ch.50 - Ecology
Ch.51 - Animal Behavior
Ch.52 - Population Ecology
Ch.53 - Community Ecology
Ch.54 - Ecosystems
Ch.55 - Conservation Biology

Facilitated Diffusion

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Sections
Fluid Mosaic Model
Osmosis and Diffusion
Facilitated Diffusion
Active Transport
Bulk Transport

Concept #1: Carrier Proteins

Concept #2: Channel Proteins

Practice: What is required for facilitated diffusion to occur?

Practice: Channel proteins are always open, allowing for a constant flow of solutes through them.

Additional Problems
If glucose needs to enter a cell: a. it will most likely do so by simple diffusion down its concentration gradient. b. it will most likely require ATP to enter a cell. c. it will most likely use a protein carrier to cross the lipid bilayer. d. it will most likely use a hydrophilic pore to cross the lipid bilayer. e. glucose doesn’t enter cells; they manufacture it.
Which of the following statements about chemically gated ion channels are true?a.  in the center of the protein a pore existsb.  the pore connects the extracellular fluid with the cytoplasmc.  the pore is big enough for ions to pass through itd. all of the above
Proteins that function as passageways through which substances and information crosses the membrane are calleda. carrier proteinsb. hydrophilic proteinsc. hydrophobic proteinsd. transmembrane proteins
Carrier-mediated transport is also calleda. facilitated diffusionb. active transportc. exocytosisd. endocytosise. phagocytosis
The type of diffusion that is specific and passive, and which becomes saturated if all of the protein carriers are in use isa. exocytosisb. facilitated diffusionc. active transportd. endocytosise. osmosis
How to move CI-across the membrane? When this protein is mutated, what kind of disease does it cause?
How do the transporters and ion channels move molecules across cell membrane? (Hint: both transporter and ion channels are proteins)
What are uniport, symport and antiport?
Which of the following statements about ion channels is FALSE?A. Ion channels are multi-subunit proteins.B. Ion channels allow ions to move against their concentration gradient.C. The selectivity of an ion channel is dependent upon the amino acids that comprise the mouth of the channel.D. Ion channels are integral membrane proteins.