Sunday, August 29, 2021


Biology Index

Where are we going with this? The information on this page should increase understanding related to this standard:  Evaluate comparative models of various cell types with a focus on organic molecules that make up cellular structures.

Article includes ideas, images, and content from Troy Smigielski (2021-08)

(Is that really the best word they could come up with for… anything?!)

Remember all that about carbohydrates being a source of energy in living things? And… if more carbohydrates are consumed than is needed, the excess energy gets stored as fat? Remember that?

If carbohydrates are full of energy and you overeat them and they get stored in fat, what do you think fat has a whole lot of?  Yeah… Energy!

Lipids function to store energy, provide insulation, and are important components of the cell membrane.

Lipids are hydrophobic which means they hate water. Not like in an emotional way. But… you know what it means!

Okay… what about those monomer building blocks? If lipids are a biomolecule and all biomolecules are made up of monomers, then… Lipids must have a monomer. 

The monomer of a lipid is a triglyceride.A triglyceride is one glycerol + 3 fatty acids
(That would make a lot more sense if we knew what glycerol and fatty acids were!)

A picture's worth 1000 words (so, they say)…

The two main elements in the fatty acid chains are hydrogen and carbon.

Structurally, a lipid is a long chain of hydrocarbons. These long hydrocarbon chains partially differentiate lipids from other biomolecules.

Lipids are composed of carbon, hydrogen and oxygen atoms, and in some cases contain phosphorus. Nitrogen, sulfur and other elements also occur occasionally.

The elements forming many common lipids are…

H hydrogen
O oxygen
C carbon

Also, in the special case of cell membranes, P phosphorus


Lipids occur in many places and fall into several main categories.

Examples of lipids are:
  • Fats
  • Oils
  • Cell Membranes
  • Waxes
  • Cholesterol
  • Steroids
  • Some hormones

So… big long hydrocarbon chains… Something about glycerol… Fats… oils… waxes…

And about that hydrophobic thing? What about that?

Fats and Oils are Lipids

So, water is a relatively dense compound of hydrogen and oxygen. (Insert long, complex discussion of electronegativity and such here… you know… basically stuff chemists care alot about.) Therefore, the water molecule is polar.

The lipid molecule is NOT polar.
So, "Lipids are non-polar molecules, which means their ends are not charged. Because they are non-polar and water is polar, lipids are not soluble in water. That means the lipid molecules and water molecules do not bond or share electrons in any way" (source, 2021-08-29).

So, it won't dissolve into water. AND, its structure causes it to take up a lot of space. Since it takes up a lot of space, it is relatively less dense than water. So…

What happens if you mix oil and water? Well, chefs know what happens when you mix oil and vinegar. And vinegar is like water (Insert long, complex discussion of acids here. Or take my word for it.) Oil and vinegar won't mix! Just look at your Italian Dressing bottle, if you don't believe me!

Okay, hang on! Let's go this way… Water is a polar molecule meaning that one "end" has a positive charge and the other a negative charge. So, opposite charges attract. Like when hair sticks to a comb or a yarn cap because of static. In essentially the same way, the positive end of one water molecule sticks to the negative end of another water molecule. In time, all of the water sticks to other water. NOT to the non-polar lips. Since water sticks to water, all of the oil ends up isolated.

So… back to basics! (Yes, please, back to basics!)

Lipids are hydrophobic which means they hate water and will not dissolve in it.

Okay… fun stuff… what else?

Fats In Food

There are two main types of fats in the food what we eat.

Saturated fats only have single bonds and are solid at room temperature. These are typically found in meats, dairy, butter, and cheese.

Sources of Saturated Fats

Unsaturated fats have at least one double bond and are liquid at room temperature. These are typically found in fish, plants, oils, and nuts.

Sources of Unsaturated Fats

Okay, that's great… and… why:

Back to that chemistry stuff, I'm afraid!

The saturated fats have a long, straight structure of single bonds between the H-C-H segments. This makes it tough for the body to break down.

The unsaturated fats have a long structure, too, but at least one of the segments has a double-bond and (because of more complex chemistry stuff), the chain bends. This makes it easier for the body to break down.

Generally, unsaturated fats are "better for you" than are saturated fats.

Lipids in Cell Membranes

The cell membrane functions to regulate what comes into the cell and what goes out of the cell. It is designed to let some things in and some things out. It relies, in part, on special lips to do this.

Phospholipids are a special kind of lipid that makes up the cell membrane.

They are arranged in a bilayer with their hydrophilic (water-lover) heads pointing outward hydrophobic (water-fearing) tails pointing inward.

Woo! There's some big words up there! Definition please!

hydrophilichaving a tendency to mix with, dissolve in, or be wetted by water.

hydrophobictending to repel or fail to mix with water.

So, the phospholipids have one end that is hydrophilic and then long, hydrophobic tails. This arrangement is very important in regulating what can and cannot enter your cells.

Small, hydrophobic molecules can fit between gaps in the phospholipid heads. However, large, charged, or hydrophilic molecules cannot pass through the membrane. 

But, the purpose of the cell membrane is to regulate what goes in and out. If most hydrophilic compounds are unable to pass through, how do they get into and out of your cells? For instance, water can pass in and out of cells as needed to keep everything in balance.

Well, phospholipids are only a part of the cell membrane. The cell membrane is more complex, and some of its parts are designed to allow things to pass through. 

Wednesday, August 25, 2021


Biology Index

Where are we going with this? The information on this page should increase understanding related to this standard:  Evaluate comparative models of various cell types with a focus on organic molecules that make up cellular structures.

Article includes ideas, images, and content from Troy Smigielski (2021-08)

(Sounds like this is the beginning of something big… or, actually small!)

Carbohydrates are one of the four types of biomolecules.

Carbohydrates function to provide immediate energy and regulate blood sugar levels.

Carbohydrates include sugars, starches, and fiber. They are essential food nutrients that your body turns into glucose to give you the energy to function. (More! 2021-08-27)

As a biomolecule, carbohydrates (like lipids, proteins, and nucleic acids) are made up of monomers. The monomer from which carbohydrates are built is a monosaccharide

"Monomer" is the name for the building blocks out of which biomolecules are formed. That means that carbohydrates are built out of monosaccharides.

Naturally, understanding what a monosaccharide is seems to come next! 

There are 5 monosaccharides in the carbohydrate above.

Monosaccharide: any of the basic (class) sugars which can be identified by the ratio of hydrogen, carbon, and oxygen present. 

So… sugars… made of carbon, hydrogen, and oxygen. 

Seems like there could be a lot more! 

Examples of monosaccharides include glucose (dextrose), fructose (levulose), and galactose. Monosaccharides are the building blocks of disaccharides (such as sucrose and lactose) and polysaccharides (such as cellulose and starch).  (2021-08-25, SOURCE)

Seems like that is way too much!

Monosaccharides can be easily identified by their chemical makeup. They are built out of Carbon, Hydrogen, and Oxygen in a specific ratio. And what is that ratio?


What that means is that for every 1 Carbon, there will be 2 Hydrogen and 1 Oxygen.


A monosaccharide always has a 1:2:1 ratio of C:H:O

In larger carbohydrates, the ratio do not match this. However, the 2:1 ratio of C:H usually holds true (hydrogen and oxygen). The C ratio will alter. (More)

And… So what?

So… since monosaccharide is the monomer for many different sugars, chemists and biologist can say things like… 

"Well, glucose is a monosaccharide. It's different from maltose, which is a disaccharide."

The illustrations above use a format wherein the points of the hexagon that are NOT otherwise labeled represent a C-H (carbon and hydrogen connected). Compare the glucose in this diagram with the one above)

That glucose is a mono… thing and maltose is a di… thing means that they are similar, differing in the number of things (saccharides) present.

ANALOGY: Think of a saccharide as one Lego® block. You can make a lot of different things depending on how you combine the blocks. You could build a house or a castle or a… Well, you know Lego®

In the same way, different combinations of saccharides (or any other monomer, for that matter) results in different things. (For instance, on saccharide (monosaccharide) is a sugar, glucose.)

Within the paradigm of monomers (saccharides for carbohydrates) carbohydrates can be broken down into three groups:
  • Monosaccharides
  • Disaccharides
  • Polysaccharides

Monosaccharides and disaccharides are sugars.

Sugars often end in -ose. For instance, glucose, maltose, fructose…

If you look close, you'll see that the monosaccharides all have the same formula (as to the disaccharides and polysaccharides. These are examples of isomers: compounds having the same chemical formulas, but in which the atoms are arranged differently.

Polysaccharides are starches.

Aside from fibre, carbohydrates are pretty much just sugars and starches.

Monosaccharides are made up of one sugar (the monomer saccharide) and are typically ring-shaped in structure. The most common monosaccharide is glucose.

Disaccharides are made up of two sugars and are created when two monomers are joined together.

Polysaccharides are made up of 3 or more sugars and are joined together through a dehydration synthesis reaction.

Starch: energy storage in plants.
Glycogen: energy storage in animals
Cellulose: major component in plant cell walls.
Chitin: support and protection (insects and fungus)


Biology Index

Where are we going with this? The information on this page should increase understanding related to this standard:  Evaluate comparative models of various cell types with a focus on organic molecules that make up cellular structures.

Article includes ideas, images, and content from Troy Smigielski (2021-08)

(Sounds like this is the beginning of something big… or, actually small!)

Living creatures… what are they made of? Cells…

So, what are cells made of?

All cells are made up of a combination of four biomolecules. That's it. Four types of biomolecules are responsible for making up every cell of every type of living things.

That's not FOUR different things… Each TYPE of biomolecule comes in a LOT of different "flavors."

But… Just four types of biomolecule make up every cell.

The four biomolecules are:
  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic acids

Well now, that seems simple enough. It must be more complicated!

Kinda. Kinda not.

Describing the different biomolecules relies on certain words for the different… things… They share a common set of prefixes.

When we study biomolecules, we’ll repeatedly come across a couple of prefixes.

Mono… means one
e.g. monounsaturated

Di… means two
e.g. dioxide

Poly… means many (more than two)
e.g. polypeptide

Okay, fair enough… 

We need to attach those prefixes to something… (Grrr… I knew it was too good to be true!)

Each biomolecule is made up of even smaller building blocks called monomers.  When you string monomers together, you create a polymer.



1. All living things are made up of cells.

2. Cells are made up of the four biomolecules…

3. …which are:

4. Each biomolecule performs certain functions in the cell.

5. Biomolecules are made up of even smaller building blocks called monomers. 

6. Monomers of the same biomolecule share some structural and chemical characteristics including what elements they are made of.

Biomolecules At A Glance



Some Functions




C, H, O

Primarily, it supplies
energy to cells.

Also a component in

plant cell walls. 

Also provides support

and protection as chitin

in bugs and fungi.








C, H, O, P

Store energy

Provide insulation

Important components

of the cell membrane.



Cell Membranes




Some hormones


Amino Acids

C, H, O, N, S

Controls cell functions


• Build muscle, tissue,

and bone

• Help fight disease

There are thousands of known proteins including…




Nucleic Acids


C, H, O, N, P

Stores genetic




Tuesday, August 24, 2021

Frame of Reference

Introduction to Chemistry and Physics Index

Physics Index

Where are we going with this? The information on this page introduces the broad topic of physics by identifying different fields within it.

Frame of Reference
(You're just making things up, now, aren't you?)

Frame of reference seems like… like… I don't know what it seems like. 

How about a purpose, then?

The purpose of having a frame of reference is to create a system (often using X, Y, and Z axes1) in which numeric values can be associated with the positions of and motion of the things within the system. Both the space and the objects within the space are related by means of the frame of reference.

1 The plural of axis is axes.

When creating a frame of reference, the end goal is to make the math easier and to make describing what's going on more clear.

And… a definition on this one is going to be… fuzzy.

Perhaps it is best to define by examples?


Think of a ball rolling. Now, think in two dimensions. Okay, NOW think of the ball rolling from the left to the right. OKAY NOW… here's the cool part!

So, we have a ball moving in 2 dimensions. Moving… that implies positions. And directions. So… 

When establishing the frame of reference for this situation, you get to decide some things… Like:

What quantities are we using to measure things? (distance, length, relative position…)
What are some units that go with those quantities?

Where is zero?
Which direction is bigger than zero (positive)?
Which direction is negative?

You can decide.

Let's say left is negative and right is positive. 

So, if the ball is at 4 on the meter stick and it moves -2 centimeters, then it moved left.

And, if it moves right 6 cm, then it moved +4 centimeters?

Thus… left is negative and right is positive.


Think of a ball rolling. Now, think in two dimensions. Okay, NOW think of the ball rolling FROM some place TO some other place.

Perhaps in this frame of reference, away from the origin is positive. As it moves away the measure of position increases. 

It started 2 meters away from a reference point. It moved further away by 2 meters. The distance from the reference point would be greater.

If it started 2 meters away and moved toward the reference point by 1 meter, the distance from the reference point would be less.


Up and down…

This is interesting to think about because, sometimes in order to make the math easier, up needs to be positive and down needs to be negative. Other times (say you want to know how far something falls) down is better as the positive and up negative.


To infinity and beyond!

Say you have two satellites, one following the other. At different velocities relative to a planet.

If the question asks about something involving only the two satellites, it might be easier to develop a frame of reference wherein one of the satellites is considered the origin and only the relative motion between the two is factored in.


A good frame of reference…

… make the math easier.

… allows clear communication of what's going on.

… is specific to a given situation.

Different frames of reference can exist for the same situation, so understanding how to interpret them is important.

Wednesday, August 18, 2021

Characteristics of Living Things

Biology Index

Where are we going with this? The information on this page should increase understanding related to this standard: Compare and contrast existing models, identify patterns, and use structural and functional evidence to analyze the characteristics of life. Engage in argument about the designation of viruses as non-living based on these characteristics.

Article includes ideas, images, and content from Troy Smigielski (2021-08)

Characteristics of Living Things
(Huh… That seems like something we should know…)

In the classic horror movie, Frankenstein, (in some versions, at least) the mad scientist, as his created monster rises from the lab table, declares, "It's alive!"

How did he know?

What makes something alive? What is the criteria used to determine if something is or is not living?


We should discuss this!

The following are eight characteristics of living things.

Cells… Cells… Cells… An important aspect of being alive is being made of cells. (Not phones! Not rooms for detaining people. You know… biology cells.)

 1. All living things are composed of cells.
    • A cell is the smallest unit of life.

    • Every living thing is composed of at least one cell.

    • Some things are unicellular (such ad bacteria) and others are multicellular (for example, humans and trees).
      • unicellular: being composed of only one cell.
      • multicellular: begin composed of more than one cell.


2. Living things maintain a stable internal environment.

All living things can control their internal conditions to keep them at a point called homeostasis, which is the equilibrium point. (Wait! What is this thing you call homeostasis? We should define that!)

Homeostasis (Greek prefix "homoios" (ομοιος) meaning "same" and the English root "stasis" meaning state or condition) is the state in which something stays the same. If a store only allows 300 people inside and admits people only when others leave, then they are keeping homeostasis with regard to people inside. 

Examples: Body temperature, solute levels in bloodstream…


3. Living things need to acquire energy to survive.

Organisms must take in materials and energy to grow, develop, and reproduce.
    • Autotrophs are organisms that can make their own food. For instance, plants can make energy by means of photosynthesis.

    • Heterotrophs are organisms that get their food from a different source.


4. Living things evolve, change, and adapt (as a group) over time.

All living things can adapt to their surroundings causing changes over many generations. (ex: bacterial resistance to antibiotics).
For instance, only the genes for coloring in rabbits that help them survive in certain terrain would be passed on. 


5. Living things reproduce.

All living things can make more organisms either sexually (plants and animals) or asexually (bacteria).

Sexual reproduction: the production of new living organisms by combining genetic information from two individuals of different types (sexes). In most higher organisms, one sex (male) produces a small motile gamete which travels to fuse with a larger stationary gamete produced by the other (female). (Source)

Asexual reproduction: Asexual reproduction occurs when an organism makes more of itself without exchanging genetic information with another organism through sex. (Source, 2021-08-19

Following are the examples of asexual reproduction:

Bacterium undergoes binary fission in which the cell divides into two along with the nucleus.

Blackworms or mudworms reproduce through fragmentation.

Hydras reproduce through budding.

Organisms such as copperheads undergo parthenogenesis.

Sugarcane can be grown through vegetative propagation. 

(Source 2021-08-19) 


6. Living things are built on a universal genetic code.

All organisms use the same code to store their genetic information. It is stored in a molecule called DNA.


7. Living things grow, mature, and develop.

    • Each organism has a pattern of growth and development.

    • In humans, we start as one cell. That cell replicates via mitosis into 2 > 4 > 8 > 16 > 32… > 30,000,000,000,000


8. Living things respond to their environment.

Organisms detect and respond to stimuli from their environment. As things happen around it, a living organism can change. A plant may grow toward the light. A human may be startled and jump when hearing a loud noise. 

To be considered a living thing, an organism must have all eight of the characteristics of life.

And… That brings us back to Frankenstein's monster… Was it alive? Hmm… If not, which of the eight characteristics of living things did it lack?

Feel free to speculate and talk among yourselves!

Monday, August 16, 2021


Biology Index

Where are we going with this? The information on this page introduces microscopes and their use.

Article includes ideas, images, and content from Troy Smigielski (2021-08)

(We should take a very close look at this! See what I did there?)

A microscope is… Okay, most people know what they are and that they allow us to look at very minute details. 

Microscopes are tools that make an enlarged image of something that is otherwise too small to see.

Microscopes differ. Not all are equal.

Microscopes have two important specifications
  • Magnification - the power to increase an object’s size
  • Resolution - the power to show details clearly
These specifications make a big difference! It's not easy to have BOTH high magnification and high resolution. But, ideally, a good, quality microscope will have strong magnification and high resolution.

Microscopes have been around for a long time. A dude named Zacharias Janssen is credited with inventing the microscope. Later, Anton van Leeuwenhoek was acknowledged as being the first microscopist. 

Later still, Robert Hooke discovered and coined the term "cell" by using a microscope to examine cork.

Microscopic Cork Image

Types of Microscopes

There are three types of microscopes! Yeah, that's right! Three!

Compound Light Microscopes

The compound light microscope is the most common type

• Uses a mirror (or other light source) that directs light upward through the specimen and into the lenses.

• Specimens can be living or non-living

• Can magnify up to 1000x.

About the Compound Light Microscope…
The compound light microscopes has an ocular lens (the one your eye goes on) and 4 objective lenses (the ones that point at the object you are trying to see).

•  The ocular lens is always 10x.

• You only use one of the 4 objective lenses at a time. The objective lenses have different powers such as:

• Scanning lens = 4x 
• Low objective = 10x 
• High objective = 40x 
• Oil immersion = 100x

The total magnification is equal to the power of the ocular lens multiplied by the objective lens.

As you magnify the image, you see less and less of it (duh). What you can see is called the field of view.

Said differently, the field of view is the diameter of the what you can see. The field of view decreases as magnification increases. 

Parts of a compound light microscope…

1. Body tube
2. Revolving nosepiece
3, 4, 5. Objective lenses
6. Stage clips
7. Diaphragm
8. Light source
9. Ocular lens (Eyepiece)
10. Arm
11. Stage
12. Course focus adjustment knob
13. Fine focus adjustment knob
14. Base

Scanning Electron Microscope (SEM)

• Uses a stream of electrons (not light) to produce an image.

• Specimens are non-living

• Can magnify up to 100,000 x

• Creates a 3-dimensional image

Transmission Electron Microscope (TEM)

• Uses a beam of electrons (not light) to produce an image

• Specimens are non-living

• Can magnify up to 200,000 x

• Looks at interior of cells