Cell Shape and Size

Explain how cell size and shape affect the overall rate of nutrient intake and the rate of waste elimination.

Smaller cells have a better rate of nutrient intake and elimination waste. [For more details, see ‘Surface Area to Volume Ratios’ and ‘SA:V and its Impact’] A spherical shape has better overall rate of nutrient intake/ waste elimination as compared to that of a cubical shaped cell, because the distance from the surface to the center of a sphere is uniform overall whereas it is not for a cube.

SA:V and its Impact

Using any model, calculate simple surface area-to-volume ratios for cubic and round cells and explaining how this impacts procurement of nutrients and elimination of wastes.

For details on the impact of SA:V, see ‘Surface Area to Volume Ratios’. The calculations below support the information provided in that post.

A high SA:V is more favorable for the best procurement of nutrients and elimination of wastes.

Cell Size Limitations

Explain the physical considerations that determine the upper and lower limits to cell size.
A cell must be large enough to fit all of its cell organelles within. But if a cell is too big, diffusion and the movement of waste/nutrients in and out of the cell will be much too slow for the cell to function properly and survive.

Key Building Blocks and Wastes

Identify several chemical elements and molecules that function as key building blocks or are eliminated as wastes.

Phosphorous - Phosphate is an inorganic chemical element plants use to grow.

Mastering Biology | Pearson; Campbell Biology

Nitrogen - Ammonia and nitrate are used by plants to grow and flourish. 

Mastering Biology | Pearson; Campbell Biology

Carbon - Carbon dioxide is used by photosynthetic organisms to create organic molecules that heterotrophs utilize.

Mastering Biology | Pearson; Campbell Biology

Carbohydrates - Sugar is used and stored in the human  body for energy. Structural polysaccharides such as cellulose are unable to be digested by the human body and therefore are eliminated as wastes. But, cellulose does help with removing cholesterol from a human’s body.

Water - Water is utilized by biological organisms and the environment for various purposes, see the following posts for more information on the cycle of water and water’s functionality:

‘Exchange of Matter’

‘Why do we need H2O?’

‘Unique Properties of Water’

Surface Area to Volume Ratios

Explain why surface-area-to-volume ratios are important in affecting a biological system’s ability to obtain necessary resources or eliminate waste products AND Explain why smaller cells have a more favorable surface area-to-volume ratio for exchange of materials with the environment.

This is a simple math problem. Let’s take a look at cuboidal cells. As the volume of a cell increases, so does its surface area. the relation between these two numbers is exponential, so as surface area increases, the volume increases at a greater rate. 

http://www.tiem.utk.edu/~gross/bioed/bealsmodules/area_volume.html

As a result of this, more material can enter the cell [because of the increased SA] but will take a greater time to reach the center as the volume has increased drastically. So, in a cell with greater SA and V, it will take a greater time to receive necessary resources and to eliminate waste products. This is why small cells are more efficient; smaller cells have a more favorable surface area-to-volume ratio for exchange of materials with the environment.

This YouTube video below shows this concept in action.

Unique Properties of Water

How does the polarity of water lead to the emergence of unique properties in liquid water?

The polarity of water is caused by the covalent bonds an oxygen molecule has with two hydrogen molecules. The resulting structure leaves water molecules open to form hydrogen bonds [weak chemical bonds between negative and positive polar covalent molecules] with other molecules, allowing water to have the ability of cohesion [one substance clings to itself through hydrogen bonding] & adhesion [one substance clings to another substance through hydrogen bonding].

http://umdberg.pbworks.com/w/page/50211460/Insane%20in%20the%20membrane,%20part%201%3A%20%20Oil%20and%20water

Because of the structure and shape of water molecules, when water freezes it expands and becomes less dense, allowing it to float on the surface. Again, this is due to hydrogen bonding. As water begins to freeze, its ability to form hydrogen bonds creates lattice-like sheets of ice which are uniform and less dense than liquid water.  

http://worldoceanreview.com/en/wor-1/climate-system/great-ocean-currents/water-a-unique-molecule/

Hydrogen bonds also gives water a high specific heat, which means that water can regulate temperature very nicely. It absorbs heat without changing drastically changing its own heat. To increase the heat of a substance, hydrogen bonds will be broken. Because water has so many hydrogen bonds, it is difficult to increase the heat by breaking a significant amount of these bonds. Water is also a master at evaporative cooling for the same reason that water is able to resist temperature change; a high amount of energy and heat is needed to break hydrogen bonds and to make water evaporate. It is because of this function that our oceans do not all vaporise into the atmosphere.

Structure of a Water Molecule

How does the structure of a water molecule relate to its function(s)?
A water molecule’s structure causes it to be polar, because the two hydrogen atoms add a positive charge to one side, and the single oxygen a negative charge on the other side. The polarity of water allows for it to be a very good solvent, and the hydrogen bonds between the oxygen atom and the hydrogen atom make water resistant to temperature change. [More detail on this in ‘Unique Properties of Water’]

Why do we need H2O?

Why do biological systems need water?

Water is means of transporting material, can be utilized as a solvent, and also functions as a coolant and lubricant. Water’s unique ability to moderate temperature and to break down substances, is what allows for water to be used like so.

It also part of dehydration synthesis [removal of a water molecule to create a bond] and hydrolysis [reverse of dehydration synthesis] which creates and breaks bonds between molecules to make something more complex, or to break down something complex. For more details on Dehydration synthesis and hydrolysis, see 'Magical Water' under 4.A.1

Water’s various unique properties make life on Earth suitable and possible for us organisms. Without water and its bonding properties many macromolecules would not exist, which would disrupt the levels or organization [see 'Why does matter matter?' for chart], causing all biological systems to be nonexistent.

Phosphorus's Purpose

What function does phosphorus serve in nucleic acids? In phospholipids?

Phosphorus is present in the phosphate functional group. 

Like nitrogen, phosphorus is also a part of nucleic acids. In DNA [which is made up of nucleic acids], It is a part of the sugar phosphate backbone which creates the ‘side rails’ of DNA, if DNA were to be seen as a ladder.

https://groups.yahoo.com/neo/groups/evolutionary-psychology/conversations/topics/138667

A phospholipid consists of two fatty acids and one phosphate group attached to glycerol. The phosphate group in the center of of the head of the phospholipid causes it to be hydrophilic. The tails of a phospholipid are hydrophobic. In a phospholipid bilayer membrane, the hydrophilic heads orient themselves to face the outside and inside the cell and help control the retention and expulsion of water and water-soluble substances.

https://commons.wikimedia.org/wiki/File:0301_Phospholipid_Structure.jpg

Nitrogen's Purpose

What function does nitrogen serve in proteins?  In nucleic acids?
A Nitrogen is a part of the amino functional group which is a component of both proteins and nucleic acids. 
Protein is made up of amino acid monomers [subunits that can join together to form more complex structures] which all have this amino functional group included in their structure. The nitrogen in this functional group that helps to form polypeptide bonds with other amino acids in order to form proteins. Polypeptide bonds are what ‘hold together’ proteins. So essentially, nitrogen helps form proteins by aiding in the bonding amino acids. 

https://thebiochemeffect.wordpress.com/tag/peptide-bonds/

Nitrogen bases In nucleic acids make up the code in DNA and RNA. There are five nitrogen bases, adenine, guanine, uracil, thymine, and cytosine. Thymine only appears in DNA, and uracil appears only in RNA. DNA and RNA dictate how an organism is built and constructed. So Nitrogen plays a very important part in nucleic acids.

https://biochemaholic.wordpress.com/

Exchange of Matter

Diagram the exchange of matter between organisms and the environment.
Water is essential to all organisms, this is a diagram of how water is exchanged between organisms and the environment.

Fish and CHONPS

Explain the uses of carbon, hydrogen, oxygen, nitrogen, phosphorous and sulfur in biological systems.
These six elements are the majority of building blocks that make up all living matter.
Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous and Sulfur are the six elements that make up functional groups. Functional groups are components of organic molecules that are involved in chemical reactions. 

There are seven such groups: 
Hydroxyl
Carbonyl
Carboxyl
Amino
Sulfhydryl
Phosphate
Methyl

These functional groups are what allow molecules to bond together and create more complex biological systems. For example, phosphorous, oxygen, and hydrogen make up the phosphate group. DNA is built from this functional group, and as a results proteins can be created from the code written in the DNA. 
These proteins can come together to make say.. a fish. Hm. I'm kind of craving Fish and Chips right now.

Why does matter matter?

Why is matter necessary for biological systems?

Matter is anything that takes up space and has mass. Without matter, atoms would not exist. Elements will not exist, compounds would be not made through chemical bonding, molecules and macromolecules wouldn’t exist. The levels of organization for all living things would be disrupted. Cell organelles would not exist, so cells themselves would not exist. If biological matter does not exist in a cellular level, biological systems cannot be created.

Levels of Organization