BIO130H1 Lecture Notes - Lecture 17: Resting Potential, Electrochemical Gradient, Passive Transport

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amaranthyellowjacket516

7 Mar 2019

School

UTSG

Department

Biology

Course

BIO130H1

Professor

Melody Neumann, Kenneth Yip

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BIO130H1 Lecture Notes - Lecture 16: Cytosol, Lipid Bilayer, X-Ray Crystallography

BIO130H1 Lecture Notes - Lecture 17: Resting Potential, Electrochemical Gradient, Passive Transport

BIO130H1 Lecture Notes - Lecture 18: Electrochemical Gradient, Symporter, Uniporter

Document Summary

Proteins involved in membrane transport: multipass transmembrane proteins, create a protein-lined path across cell membrane, transport polar and charged molecules. Ions, sugars, amino acids, nucleotides, various cell metabolites: each transport protein is selective, transport specific class of molecules, different cell membranes, have different complement of transport proteins. Channel proteins: hydrophilic pore across membrane, most channel proteins are selective. Ion channels transport a specific ion: passive transport, weak interactions with solute, faster transport by channel than transporter, several molecules pas through when open. Ion channels: found in animals, pants, microorganisms, two types, non-gated always open, k+ leak channels. Major role in generation of resting membrane potential in animal cells: always open, k+ moves out of cell. Important in the plasma membrane of animal cells. Transporter proteins: bind a specific solute, go through a conformational change that transports that solute across the membrane, transport proteins interact a lot and bind strongly.

Related Questions

1 Which of the following statements is false?

(a) CO₂ and O₂ can diffuse freely across the cell membranes.

(b) The differences in permeability between artificial lipid bilayers and cell membranes arise from variations in phospholipid content.

(d) Cells expend energy in the form of ATP hydrolysis to maintain ion concentrations that differ from those found outside the cell.

2 Cells use membranes to help maintain set ranges of ion concentrations inside and outside the cell. Which of the following ions is the most abundant inside a typical mammalian cell?

(a) Na⁺

(b) K⁺

(d) Cl^â

3 Pumps are transporters that are able to harness energy provided by other components in the cells and drive the movement of solutes across membranes, against their concentration gradient. This type of transport is called _____________.

(a) active transport.

(b) free diffusion.

(d) passive transport.

harlequinbuffalo618

During active transport in the neuron, the outside of the cell is _________________ and the inside is _______________.

positive, negative

more positive, less positive

more negative, less negative

negative, positive

In active transport, _____________ provides the energy to move molecules against their concentration gradient.

nucleus

potassium

sodium

adenosine triphosphate

________________ proteins can change shape when moving substances across the membrane.

Proteins that can be open or closed, based on different conditions, are called ___________.

bypass proteins

channel proteins

selective proteins

gated

Tunnels that allow charged ions to move easily across the plasma membrane without the use of energy are called ____________________.

channel proteins

glycolypipd proteins

phospholipid proteins

carbohydrate chains

____________ and ____________ make it easier for molecules to move across the plasma membrane.

small, negatively charged

small, positively charged

small, no charge

large, negatively charged

large, positively charged

3. In an aqueous environment, the phospholipids of a membrane____.

a) are arranged in a single layer

b) are arranged in a bilayer with the polar heads of each layerlocated at the surface

c) are arranged in a bilayer with the fatty acid tails locatedat the surface

d) are arranged in a bilayer but the phospholipids have nospecific orientation

e) dissolve

4. which of the following molecules demonstrate dual solubilitycharacteristics

a) sterols only

b) proteins only

c) phospholipids only

d) sterols and phospholipids

e) sterols, phospholipids, and proteins

5. The "mosaic" part of the fluid mosaic model refers to themembrane ____.

a) proteins

b) phospholipids

c) cholesterol

d) functions

e) layers

9. Transport of a molecule across a cell membrane by facilitateddiffusion ____.

a) does not exhibit specificity for a particular type ofmolecule

b) requires the input of energy

c) depends on a concentration gradient

d) goes against the concentration gradient

e) allows non-polar uncharged molecules to diffuse across amembrane

13. A transport system in which transport of an ion in onedirection provides the energy for active transport in the oppositedirection is known as ____.

a) primary active transport

b) active diffusion

c) secondary active transport

d) cotransport

e) osmosis

14. Cells undergo exocytosis ____.

a) to pump protons down a concentration gradient

b) when replicating

c) to secrete protein and wastes from the cell

d) to ingest nutrients

e) as a means of cellular protection

15. What is the molecular basis of familialhypercholestremia?

a) HDL enters cells using a specific receptor on the cellsurface

b) LDL enters cells using a specific receptor on the cellsurface

c) HDL exits cells using a specific receptor on the cellsurface

d) LDL exits cells using a specific receptor on the cellsurface

e) receptor-mediated exocytosis

16. Carrier molecules are utilized for ____.

a) active transport only

b) passive transport only

c) both active and passive transport

d) osmosis

e) transport of all types of molecules

17. All of the following are functions of integral membraneproteins EXCEPT ____.

a) transport of polar molecules

b) reception of chemical signals form other cells

c) cell division

d) recognition of other cells as being "like"

e) cell-cell binding

olivecod348

BIO130H1 Lecture Notes - Lecture 17: Resting Potential, Electrochemical Gradient, Passive Transport

BIO130H1 Lecture Notes - Lecture 16: Cytosol, Lipid Bilayer, X-Ray Crystallography

BIO130H1 Lecture Notes - Lecture 17: Resting Potential, Electrochemical Gradient, Passive Transport

BIO130H1 Lecture Notes - Lecture 18: Electrochemical Gradient, Symporter, Uniporter

Document Summary

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