Functions of Vacuoles

Friday, December 1, 2023

If you travel across the US you will notice near many cities a water tower. These are structures that store water for the people in the city. The water is essential for life and needs to be stored for later use. In a similar fashion, plant and animal cells have storage structures called vacuoles. 

Let’s take a look at the vacuoles found in plant and animal cells.. 

Although both plants and animal cells have vacuoles they vary greatly in their shape. 

On the left you'll notice that the vacuole for the plant cell is very large, and there's one central vacuole. In fact the central vacuole may take up between 30 to 70 percent of the plant cells volume.


In animal cells the vacuoles are smaller but you have more than one. The number of vacuoles depends on the type of animal cell.

 In general, the functions of the vacuole include:

Isolating materials that might be harmful or a threat to the cell

Containing and storing waste products

Store water

Maintaining internal turgor pressure within plant cells The turgor pressure is the force that pushes the cell membrane against the cell wall. If you have seen a plant wilt, the turgor pressure is low.

The central vacuole in plant cells Allows plants to support structures such as leaves and flowers due to the turgor pressure of the central vacuole.

Vacuoles are also found in fungal cells, protists, and some  bacteria have vacuoles.


So in summary, when you hear the term vacuole, think storage. Storage of wastes and water in cells.

Understanding Slope - Rise over Run

If you have two lines, how could you describe that one line is more steep than the other line? 

You could use slope.

Slope is the measure of the steepness of a line. It is defined as the ratio of the vertical change (rise) to the horizontal change (run). The slope of a line can be positive, negative, or zero.


A positive slope indicates that the line is rising from left to right. A negative slope indicates that the line is falling from left to right. A zero slope indicates that the line is horizontal and a vertical line has an undefined slope.

The slope of a line can be calculated using the following formula:

Slope = rise / run


  • rise is the vertical change between two points on the line

  • run is the horizontal change between two points on the line

Let’s take a look at the slope of this line

Let’s first find the rise which is 1, 2 and the run is 1 2 3 4


So the slope is 2/4

m is used to represent slope.

As you move from left to right the line goes upward so the slope is positive. 

How about this line.


Let's look at the rise -1,-2,-3,
and then the run is 1 the slope is -3.

Notice that as you move from left to right the line slopes downward so the slope is negative Also notice the slope is greater than the first line and you can see line is more steep.

So in summary, slope is a measure of the steepness of a line.

The greater the slope the greater the steepness of the line and smaller the slope the smaller the slope.

Slope Intercept Form

Translation Practice- Genetics

Wednesday, November 15, 2023

Learn how to convert a strand of mRNA into a polypeptide which is a chain of amino acides. This is called translation and it is one step of protein synthesis. mRNA is created from a template of DNA and uses the same bases except uracil replaces thymine. The strand of messenger RNA is always read from the 5 prime end towards the 3 prime end in triplets called codons. A codon is a DNA or RNA sequence of three nucleotides. There are three guidelines that should be followed when translating the mRNA. Always starts at AUG 3 Stops UAA UAG UGA Always reads 5’ to 3’
A codon chart will need to be used in order to translate the codon to an amino acid.

Here is a list of the 20 Amino Acids that go along with the Codon Chart.

alanine - ala - A 

arginine - arg - R 

asparagine - asn - N     

aspartic acid - asp - D 

cysteine - cys - C 

glutamine - gln - Q 

glutamic acid - glu - E

glycine - gly - G 

histidine - his - H 

isoleucine - ile - I 

leucine - leu - L 

lysine - lys - K 

methionine - met - M 

phenylalanine - phe - F 

proline - pro - P 

serine - ser - S 

threonine - thr - T 

tryptophan - trp - W 

tyrosine - tyr - Y

valine - val - V

Algebra 1 Review

Friday, November 10, 2023

This playlist includes the entire Algebra year in review. I start at the very basics and build from there.
You can use the playlist to either learn new material or use it as a refresher of material you have used before.

Here is a list of topics and videos completed so far. Please check back, it will take about 4 weeks to complete the entire course.

Exponents ( Whole numbers) Exponents with Fractions Scientific Notation to Standard Form What is an Expression in Math? Degree of an Expression Convert to Standard Form Evaluate an Expression Combining like Terms

Solving One-Variable Equations

An Introduction to Inequalities

Interval Notation

Solve Systems of Linear Equations with Substitution

Coordinate Plane

Domain and Range from a Graph

Convert from Standard form to Slope Intercept

Understanding Slope

Types of Natural Selection

Tuesday, October 24, 2023

Natural selection is the gradual process by which heritable traits become either more or less common in a population as a result of any or all of the following items


Competition for resources

Changes in the environment


natural selection

There are three types of natural selection




natural selection

Directional selection occurs when one or two of a traits extreme are selected A classic example is the peppered moth during the industrial revolution. In the mid 1800’s most peppered moths were white and black peppered moths were rare to see. As the industrial revolution moved forward factories were fueled by coal and became dark. By 1900 the population of peppered moths were mostly black. The black color on the dark tree was more favorable than the white color.

peppered moth

Stabilizing selection occurs when the environment selects for the average of a trait. One example is the number of eggs a bird population lays. Many birds may lay two eggs but this may not be enough for the birds to survive and four eggs may be too many birds to feed. Over time the population will stabilize around three eggs.

Disruptive selection
is the opposite of stabilizing. The average is not favorable and the extremes become favorable. For example, a population of rabbits live among black and white rocks. The fur color of the rabbits range from white to gray to black. The white and black are the extremes. Because the white and black colors can camouflage on the white and black rocks. The extremes will be selected for and the average color gray will be selected against. Over time this type of selection can lead to speciation.

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Weathering Erosion Deposition

Wednesday, October 11, 2023

I recently visited a barrier island. A barrier island is created from weathering,erosion, and deposition. Let’s take a look at these three items.

barrier island

To begin with keep in mind,

Weathering creates the sediment

Erosion carries the sediment

Deposition drops the sediment

weathering erosion deposition

Weathering of rocks is a physical or chemical change which results in the dissolving or breaking down of rock on earth

There are two major types of weathering.

Physical weathering which involves breaking rocks into smaller fragments caused by environmental factors.

There are several agents of physical weathering.


Water /waves




Chemical weathering  involves rocks being changed into a new substance. or new minerals chemically Here is an couple of examples.



Weathering creates the sediment

Erosion carries the sediment

Deposition drops the sediment

Erosion happens when rocks and sediment are picked up and moved to another place by water, wind , ice, even gravity.

There several agents of erosion.

Rainfall can cause erosion and wash sediment away.

Valley erosion occurs when rushing streams and rivers move rocks and sediment downstream.

Oceans are a huge force of erosion.

Wind is an agent  erosion.

A dust storm can be a huge force of erosion.

Ice and glaciers erode rock.


occurs when the agent of erosion slows down enough to where the sediment is deposited.

In this picture you can see an example of deposition. The water slows down and the rock, and pebbles are deposited.


Sand dunes are created by the deposition of wind.

A river delta iscreated by the deposition of a river.

What is a River Delta?

Tuesday, October 3, 2023

River deltas form when a river carrying sediment reaches a body of water, such as a lake or an ocean. As rivers flow they pick up small particles,rocks, sand and other items created from weathering and erosion. Erosion is the process in which materials are worn away and transported by natural forces such as wind or water.As a river enters a body of water like an ocean, or a lake it slows down and the sediment will begin to be deposited. Over time the sediment that is deposited will begin to build up and create a landform.This deposition of sediment may create a landform shaped like a triangle which is called a river delta.

river delta

It is so named because its triangle shape resembles the Greek letter Delta. Not all deltas are triangle-shaped. A bird-foot delta has few, widely spaced distributaries, making it look like a bird's foot. The Mississippi River forms a bird-foot delta as it empties into the Gulf of Mexico.

mississippi delta

Some famous river deltas include,

Colorado river delta

mississippi delta

Nile River Delta

nile delta

In summary, deltas form when rivers pick up sediment caused by weathering and erosion, the river slows down when it enters a body of water and this may create landforms and sometimes they will take the shape of a triangle.

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