bsc chapter 7
what two protiens participate in facilitated diffusion
-channel proteins -carrier proteins
What is a membrane made of
-double layer of phospholipids -embedded with proteins
how do channel proteins work
-quick -water and solte
how do carrier proteins work
-slower bc it has to change shape to transport -just solute
Active and passive transport of solutes across a membrane typically differ in which of the following ways?
Active transport always involves the utilization of cellular energy, whereas passive transport does not require cellular energy.
In facilitated diffusion, what is the role of the transport protein?
Transport proteins provide a hydrophilic route for the solute to cross the membrane.
Phagocytosis occurs when
a cell engulfs a large particle
The force driving simple diffusion is ________, while the energy source for active transport is ________.
a concentration gradient; ATP hydrolysis
what is the purpose of a membrane
a selective barrier that allows sufficient passage of oxygen, nutrients, and waste
For a protein to be an integral membrane protein, it would have to be _____.
amphipathic
what molecules dramatically increases the rate of diffusion of water across cell membranes?
aquaporins
hypotonic
concentration is greater inside thing so water will move in and it will expand
hypertonic
concentration is greater outside so water will move out and thing will shrink
___________ are membrane bound organelles, while _________ are not.
eukaryotes and prokaryotes
how do unsaturated fatty acids affect the membrane
increases fluidity
Endocytosis moves materials _____ a cell via _____.
into membraneous vesicles
Which of the following membrane activities requires energy from ATP hydrolysis?
movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid
Which of the following types of molecules are hydrophilic and therefore excluded from the hydrophobic portion of the phospholipid bilayer?
peripheral
The difference between pinocytosis and receptor-mediated endocytosis is that _____.
pinocytosis is nonselective while receptor mediated endocytosis is more selective
What is found in both prokaryotes and eukaryotes?
ribosome
what molecule can pass right through the membrane
same nonpolar molecules
isotonic
same on both sides
Osmosis
water moves across membrane from area of low concentration to high concentration
You can recognize the process of pinocytosis when _____.
when cell is engulfing extracellular fluid