Chapter 5: Cell Membrane and Signaling

What are the three major functions of membrane proteins

1. Move materials through the membrane 2. Involved in inter cellular recognition and adhesion 3. Receive chemical signals from the cell's external environment

What are the three factors that effect the speed of simple diffusion over a membrane?

1. The diamenter of the molecule or ion, smaller molecules diffuse faster 2. The temperature of the solution, higher temperatures tends to lead to faster diffusion because the head provides more energy for movement 3. The concentration gradient, the greater the concentration gradient the more rapifly a substance will diffuse

Which part of the cholesterol interacts with the polar region of the phospholipid layer a. Hydroxyl Group b. Methyl group c. Nonpolar rings

A . Hydroxyl Group

Which type of membrane transport requires energy input, or known as moving a substance against the concentration gradient? A. Active transport B. Facilitated Transport C. Osmosis D. Simple Diffusion

A. Active Transport

Which of these are not a component of plasma membrane? a. Nucleic acid b. Lipid c. Carbohydrates d. Steroids

A. Nucleic Acid

Write the general protein kinase catalyze

ATP+ Protein -----> ADP+ Phosphorylated protein Protein kinase on top of the arrow

What is the important characteristics of selective permeability membrane

Allows some substances, but not others, to pass through them

How does unsaturated and saturated fatty acids in the phospholipids chance the membrane fluidity?

As the temperature gets colder the saturated fatty acids are changed into unsaturated fatty acids

NAme the four types of signals and their differences between eachother

Autocrine: Affect the same cell that releases them. Ex. tumer cells Paracrine signals: diffuse to and affect nearby cells. Neurotransmitter Juxtacrine signaling: direct contact between the signaling and the responding cell, and usually involves interaction between signaling molecule Hormones: Reach receptors on distant cells

A signal transduction pathway involves all of the following except: A. Receptor B. ATP C. Signal D. Response

B. ATP

Which one of these signals occur only inside of the same cell? A. Juxacrine B. Autocrine C. Hormones D. Paracrine

B. Autocrine

Which of these situations will the a substance diffuse across the membrane the fastest? A. Polar ion B. Small Ion C. Cold Temperature D. A molecule with large diameter

B. Small ion

Is energy required for Endocytosis, exocytosis, or for both?

Both: Very energy costly to transport large molecules.

How are macro molecules released into the environment?

By secretion

A G-protein linked receptor will bind with the following except: A. GTP B. GDP C. ATP

C. ATP

Which type of channel includes a gated channel? A. Aquaporins B. Protein Channels C. Ion channels D. Carrier proteins

C. Ion channels

What does the cell wall do?

Covers the cell membrane Provides strength and rigidity to the cell

Name the signal that is counted as "Local" a. Autocrine b. Paracrine C. Juxacrine Signal D. A and B E. A and C

D. Autocrine and paracrine

Which of these can a G protein not bind to A. The G- protein-linked receptor B. GDP and GTP C. An effector protein D. Hydrogen

D. Hydrogen

Which of the following is not a good explanation for why the plasma membrane assembles the way it does? a. Water predominates both outside and inside b. They hydrophobic nature of the interior of the membrane allows it to have a level of fluidity c. The hydrophobic ends of the phospholipids avoid interacting with an aqueous environment d. The structure allows both hydrophobic and hydrophobic molecules to easily diffuse through the membrane

D. The structure allows both hydrophobic and hydrophobic molecules to easily diffuse through the membrane

How can phospholipid move in the phospholipid bilayer?

Easily move laterally along the bilayer. Rarely can they flip over to the other side (Called flip-flop)

What are the common features of membrane receptors in a cell?

Extracellular domain Transmembrane domain Intracellular domain

What type of diffusion involves moving large, polar, and/or charged molecules in and out of the membrane A: Simple diffusion B. Facilitated diffusion C. Active Transport D. Osmosis

Facilitated diffusion, needs carrier proteins but requires no energy

True or False: Endocytosis is the movement of large molecules or large quantities outside of the cell.

False: Move inside of the cell

What enzyme is responsible for returning the phospholipid back to normal after a Flip-flop

Flipase

Name the three types of carboyhydrates involved in recognition sites

Glycolipid: Carbohydrate covalently bonded to a lipid Glycoprotien: Carbohydrate chains covalently bonded to proteins Proteoglycan: Protein with even more carbohydrate molecules attached to it

What solution causes a animal cell to shrivel and a plant cell to wilt?

Hypertonic on the outside (concentration of solutes outside)

Define the three type of conditions from osmosis

Hypertonic: solution has a higher solute concentration that the other solution Isotonic: Solutions have equal solute concentrations Hypotonic: Solutions has a lower solute concentration that the other solution

What solution cause animal cells to swell and busrt and plant cells to become turgid cells?

Hypotonic on the outside (dilute solutes outside)

Chemical signals are separated into whether or not they can diffuse through the membrane, two types are intracellular and membrane. Name their location and their function as a chemical signal.

Intracellular receptors: Located inside the cell, small or non polar ligands can diffuse across the phospholipid layer of the cell membrane and enter the cell Membrane receptors: located outside of the cell, large or polar ligands cannot cross the lipid bi layer. Needs to bind to a transmembrane receptor with an extracellular ligand-binding domain

What solution cause the cells to be normal?

Isotonic solutions (equal solute concentrations)

What are the two factors that affect Membrane fluidity?

Lipid Composition and Temperature

What role does cholesterol play in the membrane?

Modulating the membrane fluidity

What ions are involved in the sodium-potassium pump? How many of each of these ions are pumped through the pump with each molecule of ATP?

Na+ and K+ Two K+ and three Na+

In terms of "high/low" What does the potassium and sodium need to be kept at?

Needs to maintain high K+ and low Na+ inside of the cell

What are the two type of ways substances can cross biological membranes

Passive transport: Do not require energy to be put in. Moves from higher concentration to lower concentration Active transport: Require the input of metabolic energy. Movement against their concentration gradient

Name and describe the two types of general membrane proteins

Peripheral membrane proteins: lack exposed hydrophobic groups and therefor not embedded in the bilayer Integral membrane proteins: embedded int he hydrophobic part of the bilayer

What is the difference between phagocytosis and pinocytosis?

Phagocytosis is cell eating: Large particles or entire cells are recognized and moved into the cell Pinocytosis: is cell drinking. Vesicles bring fluids and dissolved substances into the cell

Name and describe the three types of endocytosis

Phagocytosis: Eat: receptors in the cell membrane recognize a specific ligand on the surface of a large particle or even an entire cell. Pinocytosis: Drink: Vesicles bring fluids and dissolved substances, including proteins, into the cell. Receptor-mediated endocytosis: a mechanism for bringing specific large molecules, recognized by specific receptors, into the cell.

What the four primary components of the plasma membrane?

Phospholipids Cholesterol Proteins Carbohydrates

How does cholesterol maintain plasma membrane integrity

Prevents tight packing at cooler temperatures and restrains movement at higher temperatures

Name and describe the two basic types of active transport

Primary active transport: Involves the direct hydrolysis of ATP, which provides the energy required for transport Secondary Active Transport: Does not use the ATP directly. Instead its energy is supplied by an ion concentration gradient or an electrical gradient

Name and describe the difference between protein kinases and protein phosphatases

Protein kinase transfer a PO4 group onto a target protein Protein phosphatases remove a phosphate group from a protein

Name the three amino acids that protein kinase will transfer a PO4 group onto

Serine, Theronine, or Tyrosine

What are the three types of modes of molecular transport in a cell?

Simple diffusion Facilitated diffusion Active transport

What can pass by simple diffusion?

Small, uncharged, hydrophobic, non-polar molecules

A Ligand-gated ion channel does what when a ligand binds?

The channel will change shape when a ligand binds

What is osmosis?

The diffusion of free water molecules across a selectively permeable membrane

How do carrier proteins transport substances across the membrane, use the glucose transporter as an example.

The molecules binds to a specific site on the protein causing the protein to change its shape and release the substance on the other side of the membrane. For glucose the glucose molecule binds to a site on the protein, the protein changes its three dimensional shape and release glucose to the other side of the membrane

What are the differences between peripheral and integral membrane proteins?

The peripheral is located in the hydroplilic region, or outer part of the bilayer The integral membrane is inside of the bilayer, binding with the nonpolar region on the bilayer.

What is the general design of the fluid mosaic membrane?

The phosphor lipid bilayer "Proteins float in a lake of phosphlipids"

Exocytosis involves the movement of what in what direction?

This is the process in which materials are

Why is energy required for active transport?

This type of transport moves substances against their concentration gradient

What type of protein span the entire membrane?

Transmembrane proteins: Amino acid R-groups are key for this organization

True or False: Exocytosis is the movement of large molecules or large quantities outside of the cell.

True

Name a type of second messenger

cAMP: Cyclic AMP