IB Bio: Water & Membrane Transport

Properties of Water

100

This term refer's to water molecules' tendency to stick to one another:

Cohesion

200

This is an emergent property of water that arises from water molecules' ability to stick to each other AND to stick to other surfaces (i.e. this property is the sum of two other important properties); it creates biologically important interactions at the interface between water and air

Surface Tension

300

Many substances dissolve well in water, based on their chemical properties; molecules with more partial (or full) charges dissolve more easily in water. In other words, water is very good at dissolving molecules that are:

Polar

400

This is a physical property that describes how much energy is needed to alter the temperature of a substance by one degree Celsius. Water, notably, has a very high value for this property, meaning it takes a lot of energy gain or loss to change water's temperature. What is this property?

Specific Heat Capacity

500

This is a property of water (and other liquids) by which the pressure of the liquid's molecules pushing on an object which is less dense than the liquid can cause that object to float; this property/effect is called:

Buoyancy

Osmosis

100

Is osmosis a form of active or passive transport?

Passive

200

A section of plant tissue is found to have cells with a sugar concentration of roughly 1%. This tissue is placed in sugar water with a sugar concentration of roughly 0.5%. Based on this setup, will the plant tissue gain or lose mass?

Gain

300

The human organ most directly involved in maintaining the osmotic balance of the blood is the:

Kidney

400

A root system of a tree is found to have ψ = 0.2, and the soil is found to have ψ = 3.0.  Based on this information, will the roots of this tree be expected to gain or lose water?

Gain

500

Plant tissues perform optimally in hypotonic environments because their ____________ is increased

Turgor pressure

Membrane Structures

100

There are many types of molecules which comprise a cell membrane, but the primary molecule type which makes up most of the membrane is:

Phospholipids

200

Many types of membrane proteins exist which have many different functions and structural arrangements. Membrane proteins that are fully embedded into and across both sides of the bilayer of the cell membrane are referred to as:

Integral Proteins

300

This is a term for a membrane protein which carries molecules across the cell membrane against their concentration gradient at the cost of ATP:

Pump Protein

400

These are a special class of membrane proteins which have been modified to have long sugar chains attached to them, usually allowing them to carry out functions such as cell-to-cell communication. The name for this type of special molecule type is:

Glycoproteins

500

This is the molecule that many cell types will embed into their cell membranes in order to help regulate cell membrane fluidity. At high temperatures, this molecule serves to slow down the flow of molecules in the membrane, and at low temperatures it will act as a "spacer" between adjacent molecules to keep them from becoming stuck in place and impairing cell membrane function. This molecule is known as:

Cholesterol

Membrane Transport

100

Small, mostly uncharged molecules are capable of moving directly across the cell membrane relatively easily from high to low concentration. This form of cell transport is known as:

Simple Diffusion

200

GLUT1 is a protein that assists in transporting glucose from the bloodstream into cells. Notably, GLUT1 only functions when transporting glucose down its concentration gradient (from high concentration to low concentration). This means that the type of cell transport carried out by GLUT1 is:

Facilitated Diffusion

300

Due to a combined effect of the properties of the cell membrane bilayer as well as all of the molecules attached to it or embedded in it (i.e. proteins, etc.), a cell can directly or indirectly control the transport of particular types of molecules and at specific rates. This ability / property of the membrane is known as:

Selective Permeability

400

This is the term for the small, mostly temporary organelles which may be formed to transport large amounts of material at once either into or out of the cell:

Vesicles

500

This gif shows human blood collected from a patient and spread onto a microscope slide. In the image, a white blood cell chases down a bacterium and engulfs with its cell membrane, forming a membrane-bound compartment to bring the bacterium inside itself. This kind of cell transport is specifically known as:

Phagocytosis 

Chemistry

100

These are the negatively-charged particles which orbit atomic nuclei and interact to form chemical bonds:

Electrons

200

A pure substance consisting of only atoms with the same number of protons is called a(n):

Element

300

Atoms of some elements may share electrons with one another in order to fill their outermost electron shell, and this process creates chemical bonds. What are these chemical bonds called?

Covalent Bonds

400

Atoms of different elements have nuclei of differing sizes / numbers of protons, and as a result they attract electrons with differing degrees of strength. This property by which an atom of an element may attract additional electrons is known as:

Electronegativity

500

These are weak bonds which may form between partial positive charges and partial negative charges on adjacent molecules:

Hydrogen Bonds

Misc

100

This is the term for the process by which the partial positive and partial negative charges of water molecules allow them to easily dissolve and sometimes pull apart certain substances:

Solvation

200

This is a physical concept that describes all of the potential energy stored in a volume of water based on variables such as dissolved solute and pressure (as well as others not discussed in our class).

Water Potential

300

These are a special class of channel proteins with the specific function of transporting water molecules more rapidly across cell membranes:

Aquaporins

400

The resting potential (i.e. voltage difference) across the cell membranes of neurons allows them to be ready to send electrical signals by depolarizing. This resting potential is maintained mostly by a specific type of transport protein. Name this specific type of protein.

Sodium-Potassium Pump 

500

This is the name of an organelle found in some freshwater microbes (ex. paramecia) that allows them to expel water in order to maintain osmotic balance in a hypotonic environment. 

Contractile Vacuole