BIOL107 Lecture Notes - Lecture 8: Phospholipid, Phagocytosis, Golgi Apparatus

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cerisegiraffe538

24 Sep 2015

School

University of Alberta

Department

Biology (Biological Sciences)

Course

BIOL107

Professor

Torah Kachur

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BIOL107 Full Course Notes

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When there is a difference in concentration of a charged molecule across a membrane. An example of how chemical gradient can act as a source of energy for active transport. A chemical gradient or electrical gradient (or both) is a source of potential energy. When one gradient is used to power the transport of another molecule up its gradient. Example: 3 na+ up its gradient, out of the cell, powered by the transport of 2 k+ with its gradient, into the cell. Example: glucose is transported up its gradient, into the cell, powered by the transport of na+ down its gradient, also into the cell. Molecules that must enter or exit the cell but are too large to pass through a transport protein must be transported using a bulk transport mechanism. The membrane is flexible and can bend into different shapes that is then pinched off into vesicles. Bulk transport happens in eukaryotes, not prokaryotes.

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

Cellular biology answer check. please check if my answers arecorrect or not.

1) The concentration of ions inside a cell is the same as theirconcentration outside of the cell. True or false? (i chose falsesince having equilibrium inside a cell is bad)

2) Membrane transport proteins...

a)...transport membrane potentials between cells

b)	...transport membranes from the ER to the Golgi

c)	...are made up of phospholipids

d)	...transport molecules across membranes

i chose d

3)The electrochemical gradienttakes into account:

a)	The concentration of solutes on either side of themembrane.

b)	The overall charge on either side of the membrane.

c)	Both of these.

i chose C. (although i am sure that overall charge matters, Iwasn't sure if concentration of solutes are taken account.)

4) If no energywere expended by an animal cell:

a)	Both gradients would be depleted

b)The K+ gradient would maintain itself.

c)	None of these

d)	The Na+ gradient would maintain itself.

I chose d) mainly because I think Na+ gradient exist in animalcell and not K+ gradient.

5) Which of the following is a true statement aboutactin?

a)	Once actin has polymerized, it never depolymerizes.

b)	Actin is a transmembrane protein.

c)	Actin can form branched networks.

d)	Actin filaments are organized into hollow tubes.

I chose c. can't explain why.

6)Ion channels:

a)	Form a hydrophobic channel through the membrane

b)	Have filters that let sugars through

c)	Are selective for particular ions (only the

taupeshark376

Please help! Not sure about these questions..thanks

Which can cross the phospholipid bilayer of a membrane without assistance from transport proteins?

	A.	Ions such as Na+.
	B.	Small hydrophobic molecules such as O2.
	C.	Small hydrophilic molecules such as glucose.
	D.	Any small molecule or ion.

QUESTION 2

Which transport process requires a cell to expend energy?

	A.	Moving a solute up its concentration gradient.
	B.	No transport processes require energy.
	C.	Moving a solute either up or down its concentration gradient.
	D.	Moving a solute down its concentration gradient.

QUESTION 3

Imagine a cell whose membrane is permeable to water, but impermeable to solute X. If solute X is more concentrated outside the cell than inside, which way will water move by osmosis?

	A.	Water will not move in either direction, in or out of the cell.
	B.	Water will move equally in both directions, in and out of the cell.
	C.	Water will leave the cell.
	D.	Water will enter the cell.

QUESTION 4

The cellular structure that encloses the DNA/genes is the

		ribosome.
		plasma membrane.
		nucleus.
		mitochondrion.

QUESTION 5

The part of metabolism that builds larger, more complex molecules or structures from smaller, simpler components is

	A.	anabolism.
	B.	catabolism.
	C.	catalysis.
	D.	hydrolysis.

QUESTION 6

In an exergonic reaction

	A.	the reactants have more energy than the products, so energy is absorbed.
	B.	the reactants have more energy than the products, so energy is released.
	C.	the reactants have less energy than the products, so energy is released.
	D.	the reactants have less energy than the products, so energy is absorbed.

BIOL107 Lecture Notes - Lecture 8: Phospholipid, Phagocytosis, Golgi Apparatus

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