Chapter 5 - The Working Cell

Q: What is diffusion?
A: Diffusion is the passive movement of a solution across a membrane in order to evenly spread out in the available space.
Q: What is a hypotonic solution?
A: A hypotonic solution is a solution with a solute concentration lower than that of the cell.
Q: What is facilitated diffusion?
A: Facilitated diffusion is when a protein makes it possible for a substance to move down its concentration gradient.

Five Main Facts:
1) A cell will shrink in a hypertonic solution and swell in a hypotonic solution. This is the tonicity of a cell.
2) Energy is the capacity to perform work. Cells use energy as well as store it in many different ways for many different uses.
3) Chemical reactions are present in all cells. They require energy and yield products rich in potential energy.
4) Enzymes are protein catalysts that decrease the energy of activation.
5) Membranes are a fluid mosaic, with protein molecules embedded in a phospholipid bilayer.

This is a diagram of a phospholipid bilayer. It consists of proteins and other molecules that allow certain compounds to flow in and out of the cell.

Chapter five described how cells allow for atoms to flow in and our freely. The use of diffusion, passive transport and active transport allow for this to happen. A cell must have energy in order to perform many of these functions. Chemical reactions are also a necessity for the function of a cell. 

Key Terms:

1) Osmosis: diffusion of water molecules across a selectively permeable membrane

2) Tonicity: the ability of a solution fo cause a cell to gain or lose water

3) Isotonic: a cell in an equal volume of solute

4) Hypotonic: solution with a solute concentration lower than that of the cell

5) Hypertonic: solution with a higher solute concentration

6) Facilitated diffusion: when proteins make it possible for a substance to move down its concentration gradient

7) Pinocytosis: cellular drinking

8) Entropy: a measure of disorder

9) Kinetic energy: energy of motion

10) Heat: thermal energy, a form of kinetic energy associated with the random movement of atoms of molecules

http://www.youtube.com/watch?v=sdiJtDRJQEc

Chapter 4 - A Tour of the Cell

Q: What microscope are used to study a cell
A: There are two types of microscopes used to study a cell. A light microscope and the different variations of the electron microscope are two kinds of microscopes used to view cells.
Q: How small is the average cell?
A: The majority of cells found in living organisms are microscopic. There are very few cells that can be seen individually without a microscope.
Q: What's the difference between a prokaryotic and eukaryotic cell?
A: The difference between a prokaryotic cell and eukaryotic cell is for one a prokaryotic cell is much smaller. Also prokaryotic cells lack organelles which makes them much less complex. Eukaryotic cells are what make up the majority of organisms whereas prokaryotic cells are generally things like bacteria and what not.

Five Main Facts:
1) Biological membranes are composed of a phospholipid bilayer that has proteins in it as well as attached to it.
2) The nucleus of a cell is surrounded by a porous membrane that acts as a barrier. Within this barrier is the DNA of a cell which is necessary for the reproduction of a cell.
3) Vacuoles are found in plant cells and are used to store food and water as well as to help create food.
4) The cytoskeleton is a structural suport made of protein fibers. This reinforces the cell and gives it rigidity.
5) Plant cells have a cell wall unlike animal cells. This allows for them to have a rigid layer hence allowing them to grow in the fashion they do. Trees could not be made by an animal cell due to the lack of a cell wall.

This picture shows what a cell consists of. As you can see by the labels a cell has many different organelles, some with very similar functions. 

Chapter 4 walked the reader through a cell. It started out by stating how a cell can be viewed and studied. From there it went on to talk about the two different types of cells and what difference/similarities they had with each other. A cell has many different organelles all with their functions. Some of the mentioned organelles were the nucleus, ribosomes, ER, golgi apparatus, lysosome, vacuole and peroxisomes. 

Key Terms:

1) Organelles: little organs that perform specific functions for a cell

2) Chromatin: a complex of proteins and DNA

3) Nuclear envelope: a double membrane perforated with protein-lined pores and controls the flow of materials in and out of the nucleus

4) Lysosome: houses digestive enzymes enclosed in a membranous sac

5) Vacuoles: membranous sacs that have a variety of functions

6) Chloroplasts: organelles that photosynthesize and create food for plant cells

7) Cytoskeleton: network of protein fibers that give structure of a cell

8) Integrins: span the membrane and attach the other side to proteins connected to microfilaments of the cytoskeleton

9) Cell wall: distinguishes plant cells from animal cells as well as gives the plant cell more rigidity

10) Flagella: projection that helps propels a prokaryotic cell through a liquid

http://www.youtube.com/watch?v=QGAm6hMysTA

Chapter 3- The Molecules of Cells

Q: How are monosaccharides formed?
A: Monosaccharides are formed when some multiple of CH2O join together to form a carbohydrate.
Q: What is so bad about anabolic steroids?
A: Anabolic steroids are bad because they are a synthetic hormone of testosterone. When anabolic steroids are used by an individual on a regular basis it can stop the natural release of male hormones in the body. Effect of using this drug range from high blood pressure, liver damage to reduced sex drive and infertility.
Q: How strong are peptide bonds?
A: Peptide bonds are covalent chemical bonds between a carboxyl ground and amino group. This are very strong bonds since they are covalent.

Five main facts
1) Proteins can be found in all structures of life and are necessary to the functions of life.
2) There are four structures of protein, primary, secondary, tertiary, and quaternary.
3) Lactose tolerance is only a new event in human history. In the last 9,000 years since cattle has been domesticated anyone with the lactose tolerant gene was favored and hence survived better then those who didn't have it.
4) There are six functional groups, hydroxyls, carbonyls, carboxyls, aminos, phosphates, and methyl groups.
5) Organic compounds must have carbon present in the structure.

This diagram shows one way of depicting the structure of a molecule. This specific depiction of a molecule is called a ball-and-stick model. The four white balls are hydrogen and the center black ball is a carbon atom.

Chapter 3 was an overview of what cells are made up of in terms of molecules. All living organisms and other organic compounds contain carbon. This is what constitutes an organic compound. The structures of compounds were discussed and how they affect different functional groups in terms of being either a monosaccharide or a polysaccharide. There are many different structures, molecules, atoms, groups that are present in a cell. They are all necessary for a cells function.

Key Terms:
1) Organic compound: any compound containing carbon
2) Carbon skeleton: chain of carbon atoms in an organic molecule
3) Functional group: first five chemical groups
4) Macromolecules: molecules that are large in comparison to the majority of other molecules
5) Monomers: building blocks of polymers
6) Hydrolysis: the breaking of bonds by using water and adding it to the monomer
7) Saturated: fats with the maximum number of hydrogens
8) Protein: a polymer constructed from amino acid monomers
9) Denaturation: polypeptide chains unravel, losing their specific shape as well as their function
10) Primary structure: structure of a protein with a unique sequence of amino acids

http://www.youtube.com/watch?v=SYNwuLL_pOE