Topic 1 & 2

Eukaryotic cells/Prokaryotic cells (similar)

Both have a lipid bilayer,and both use DNA (genetic information)

Active Transport

a kind of cellular transport where substances move against a concentration gradient. The direction is from an area of lower concentration to an area of higher concentration.

Multicellular

plants,animals,fungi

Diffusion

The net movement of molecules from an area where they are at a higher concentration to areas where they are at a lower concentration. Due to the random movement of the molecules.

Have organelles

Cell membrane protect and organize cells. All cells have an outer plasma membrane that regulates not only what enters the cell, but also how much of any given substance comes in. Unlike prokaryotes, eukaryotic cells also posses internal membranes that encase their organelles and control the exchange of the essential cell components.

Small nonpolar molecules

can pass through the lipid bilayer and do so by squeezing through the phospholipids bilayers. They don't need proteins for transport and can diffuse across quickly.

aquaeuous

water based

What are the parts of a phospholipid? Are they polar or nonpolar?

Phospholipids consist of a glycerol molecule, two fatty acids, and a phosphate group that is modified by an alcohol. The phosphate group is the negatively-charged polar head, which is hydrophilic. The fatty acid chains are the uncharged, nonpolar tails, which are hydrophobic.

intraceullular side

inside

Unicellular

made of on cell,bacteria,protists

What are cell membranes made of?

A cell consists of three parts: the cell membrane, the nucleus, and, between the two, the cytoplasm. With few exceptions, cellular membranes — including plasma membranes and internal membranes — are made of glycerophospholipids, molecules composed of glycerol, a phosphate group, and two fatty acid chains. Glycerol is a three-carbon molecule that functions as the backbone of these membrane lipids.

What is a virus?

A virus is a small collection of genetic code, either DNA or RNA, surrounded by a protein coat. A virus cannot replicate alone. And a nucleic acid genetic material inside. Are much smaller than cells

What parts do all cells have?

All cell consist of three parts:the cell membrane, the nucleus and between the two the cytoplasm.

Reproduce through binary fission

Binary fission is a type of a asexual reproduction where a parent cell divides, resulting in two identical cells, each having the potential to grow to size of the original cell

Able to self repair

Cell membrane repair repurposes mechanisms from various cellular functions,including vesicle trafficking, exocytosis,and endocytosis, to mend the broken membrane.

How does it compare to cells? (compares cell to virus)

Cells have a double stranded DNA molecule and many strands of single stranded RNA as the copies. Viruses, however can have a double stranded DNA,single stranded DNA,double stranded RNA,or single stranded RNA/

Have protein channels

Channel proteins are water filled pores that enable charged substances (like ions) to diffuse through the membrane into or out of the cell. In essence, they provide a tunnel or such polar molecules to move through the non polar or hydrophobic interior of the bilayer.

Ions (charged particles)

Charged atoms or molecules of any size cannot cross the cell membrane via simple diffusion as the charges are repelled by the hydrophobic tails in the interior of the phospholipid bilayer.

Hypertonic

If a cell is placed in a hypertonic solution, there will be a net flow of water outof the cell, and the cell will lose volume. A solution will be hypertonic to a cell if its solute concentration is higher than that inside the cell, and the solutes cannot cross the

Hydrotonic

If a cell is placed in a hypotonic solution, there will be a net flow of water into the cell, and the cell will gain volume. If the solute concentration outside the cell is lower than inside the cell, and the solutes cannot cross the membrane, then that solution is hypotonic to the cell.

Passive transport

In passive transport, substances (e.g. ions and solutes) move across a membrane from a region of their higher concentration to a region of their lower concentration.

How do phospholipids arrange themselves in groups around oil? Around water?

In water or aqueous solution, phospholipids tend to arrange themselves with their hydrophobic tails facing each other and their hydrophilic heads facing out

Hydrophobic-tails Hydrophilic-head

One end, the "head," is attracted to water, and the other end, the "tail," is repelled by water.

Small, polar molecules

Recall that the interior of the phospholipid bilyer is made up fo the hydrophobic tails. It won't be easy for the water molecules to crosscut they can cross without the help of proteins. This is somewhat a slower process.

How the following types of molecules cross the cell membrane, and why they need to cross that way. (Large, polar molecules)

The charge of an ion, and the size and charge of large polar molecules, makes it too difficult to pass through the nonpolar region of the phospholipid membrane without help.

Facilitaed diffusion

The diffusion of solutes through transport proteins in the plasma membrane. A type of passive transport. Even though facilitated diffusion involves transport proteins, it is still passive transport because the solute is moving down the concentration gradient.

What is the fluid mosaic model?

The fluid mosaic model of the plasma membrane describes the plasma membrane as a fluid combination of phospholipids,cholestrol,and proteins. Carbohydrates attached to lipids (glycolipids) and to proteins (glycoproteins) extend from the outward facing surface of the membrane.

Where will polar molecules attach to the phospholipids?

The hydrophilic regions of the phospholipids tend to form hydrogen bonds with water and other polar molecules on both exterior and interior of the cell

Osmosis

The movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules, through a cell's partially permeable membrane.

How do cell membranes behave? What does it mean for them to be? (flexible)

The plasma membrane must be sufficiently flexible to allow certain cells, such as red blood cells and white blood cells, to change shape as they pass through narrow capillaries.

What do the different parts of cell membranes do?

The principal components of the plasma membrane are lipids (phospholipids and cholesterol),proteins, and carbohydrates. The plasma membrane protects intracellular components from the extracellular environment. The plasma membrane mediates cellular processes by regulating the materials that enter and exit the cell.

Endocytosis

The process of taking a particle or substance from outside of the cell and transferring it inside the cell using a vesicle.

Exocytosis

The process of taking a substance or particle from inside of the cell and transferring it to outside the cell using a vesicle.

Large non polar molecules

These rings can pass through but it is also slow process.

Where will nonpolar molecules attach to the phospholipids?

They interact with other non-polar molecules in chemical reactions, but generally do not interact with polar molecules. When placed in water, hydrophobic molecules tend to from a ball or cluster. The hydrophilic regions of the phospholipids tend to form hydrogen bonds with water and other polar molecules on both exterior and interior of the cell. Thus, the membrane surfaces that face the interior and exterior of the cell are hydrophilic.

Prokaryotic cells (differences)

does not have a nucleus multicellular, ribosomes smaller

extracellular

outside

Eukaryotic cells (differences)

ribosomes larger, membrane bound nucleus, either unicellular or multicellular

Homeostasis

the ability of cells and organisms to maintain stable internal conditions,even when the outside environment changes