BIOL 2160 Study Guide - Midterm Guide: Resting Potential, Fluid Mosaic Model, Fluid Compartments

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5 Apr 2018

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Fluid mosaic model phospholipids move around like a liquid, mosaic made up of many different things. The membrane is non-polar: anything polar cannot pass through the membrane. Small or non-polar molecules can freely diffuse across the membrane. Large or polar molecules need carrier proteins to move across membrane. Cha(cid:396)ges (cid:373)ole(cid:272)ules (cid:272)a(cid:374)"t (cid:272)(cid:396)oss (cid:449)ithout help of othe(cid:396) p(cid:396)otei(cid:374)s (cid:374)o si(cid:373)ple diffusio(cid:374), so io(cid:374) (cid:272)o(cid:374)(cid:272)e(cid:374)t(cid:396)atio(cid:374)s do(cid:374)"t e(cid:448)e(cid:374)tuall(cid:455) even out. Sodium and potassium (k+ and na+) basically control resting membrane potential of all cells: always much more sodium outside the cell than inside, always much more potassium inside the cell than outside. Driving force 3 types: difference in energy across a membrane. + environment inside the cell repel + charges: all negative membrane potential more negative inside the cell than outside. Chemical force wants sodium to go into the cell, but electrical force wants sodium to leave the cell.

Related Questions

1,Match the descriptions to the type of transport.

- A. B. C.	Water enters a cell because it is hypertonic compared to the extracellular environment, increasing its turgor pressure
- A. B. C.	Water enters guard cells because the guard cells are hypertonic compared to the surrounding cells
- A. B. C.	Potassium ions are pumped into guard cells
- A. B. C.	The motor cells of a Venus fly trap are hypotonic compared to surrounding cells, causing water to leave the motor cells
- A. B. C.	Sugar is loaded into the phloem

A.	Both active and passive transport
B.	Passive Transport
C.	Active transport

2,Describe what is wrong with the following statement and explain why:

All prokaryotic and eukaryotic cells contain plasma membrane, nucleus, ribosomes, organelles, cytoplasm, and cell walls.

What is short-distance transport?

	a,	The movement of solutes from a region of low concentration to a region of high concentration
		b,The movement of water, nutrients, and other substances between cells
c,		The movement of substances from a region of high concentration to a region of low concentration
d,		The movement of water across a semipermeable membrane from a region of low solute concentration to a region of high solute concentration.

What terms describe the movement of water across a semipermeable membrane from a region of high water concentration towards a region of low water concentration (and high solute concentration.)

What is found in the proptoplasm?

Cell wall, cytoplasm, plasma membrane, nucleus, and other cell organelles

Plasmodesmata, cell wall, and plasma membrane

Cell wall, cytoplasm, and plasma membrane

Cytoplasm, nucleus, and other cell organelles

The channels that allow nutrients and protoplasm to pass between plant cells are called _________________.

What happens when a plant cell is placed in a hypotonic solution?

Water will enter the plant cell and the plasma membrane will swell and cell lysis will occur

Water will leave the plant cell and the plasma membrane will pull away from the cell and plasmolysis will occur

Water will enter the plant cell and the plasma membrane will swell and push against the cell wall

Water will leave the plant cell and the plant cell will lose turgor pressure, causing the plant to wilt

________________ transport uses cellular energy.

What molecules make plasma cell membranes hydrophilic on the outside and hydrophobic on the inside?

What type of cells do plants have?

		Bacterial
		Archaeic
		Eukaryotic
		Prokaryotic

A hypertonic solution has a higher level of solutes so the water moves out of the cells to the surroundings

A hypotonic solution has a higher level of solutes so the water moves out of the cells to the surroundings

The salt and water solution in the potato is a hypotonic solution

Osmosis is the movement of large molecules across a membrane which require embedded proteins

The plain water in this experiment is the solvent and the salt is the solute.

Passive transport requires no energy and the molecules move with the concentration gradient or from high concentration to low concentration

Active transport required no energy and the molecules move with the concentration gradient or from high concentration to low concentration.

The water on the inside of the potato with the salt molecules is an isotonic solution the same as the solution on the outside of the potato.

Water will not move by simple diffusion (osmosis) into or out of cells it requires energy or protein transporters

The solution of salt water in the potato has a lower concentration of water molecules so the water on the outside should move into the cells

Question 1

Plasma membranes are selectively permeable. This means that

	A.	glucose cannot enter the cell.
	B.	the plasma membrane allows some substances to enter or leave a cell more easily than others.
	C.	plasma membranes must be very thick.

Question 2

Oxygen molecules O₂ crosse a plasma membrane by

	A.	passive transport
	B.	osmosis
	C.	active transport

Question 3

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.

		A. energy and channel proteins; against (up)
		B. transport proteins that make channels ; down
		C. energy ; down

Question 4

When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will

		A. move to the side with lower water concentration
	B.	move to the side with higher water concentration
	C.	move to the side with lower solute concentration

Question 5

Kinetic energy differs from chemical energy in that

	A.	chemical energy is a particular form of kinetic energy.
	B.	kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.
	C.	kinetic energy is stored energy that has the potential to do work, and chemical energy is the energy of movement.

Question 6

When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction.

	A.	exergonic; endergonic
	B.	endergonic; exergonic
	C.	spontaneous; exergonic

Question 7

When an enzyme catalyzes a reaction

		A. it raises the activation energy of the reaction.
		B. it lowers the activation energy of the reaction.
		C. it is used once and discarded.

Question 8

Which of the following statements regarding enzyme function is false?

		A. An enzyme's function depends on its three-dimensional shape.
		B. Enzymes are very specific for their substrates.
		C. Enzymes are used up when they catalyze a chemical reaction so must be synthesized for each new chemical reaction

BIOL 2160 Study Guide - Midterm Guide: Resting Potential, Fluid Mosaic Model, Fluid Compartments

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