Cells. Warm Up Activity On page in your journal write down how many cells you have in your body. The average human person’s body is composed of around.

Cells

Warm Up Activity

• On page in your journal write down how many cells you have in your body.

• The average human person’s body is composed of around a hundred trillion cells (100,000,000,000,000).

• But there are even MORE cells than that living in you! You have trillions and trillions of bacteria living in you too! (Even more bacteria than number of cells your body is made of).

All living things are composed of cells

• Some organisms are composed of just one cell Some organisms are composed of just one cell (like these bacteria you can see on this slide).(like these bacteria you can see on this slide).

• Other organisms (like plants, animals, and Other organisms (like plants, animals, and humans) are composed of trillions of cells. humans) are composed of trillions of cells.

• To help us get a better idea of how many cells To help us get a better idea of how many cells we have, let’s take a look at we have, let’s take a look at this video..

2 major types of cells2 major types of cells

ProkaryotesProkaryotes EukaryotesEukaryotes

BacteriaBacteriaPlants, Fungi Animals, Humans, etc.Plants, Fungi Animals, Humans, etc.

SimilaritiesSimilaritiesProkaryotic CellProkaryotic Cell Eukaryotic CellEukaryotic Cell

• Both prokaryotes and eukaryotes have DNA Both prokaryotes and eukaryotes have DNA ((DDeoxyriboeoxyribonnucleic ucleic AAcid).cid).

• Both have a cell membrane (a layer of lipid (fat)) Both have a cell membrane (a layer of lipid (fat)) surrounding it to protect it from the outside surrounding it to protect it from the outside environment and control what comes in and out environment and control what comes in and out of the cell.of the cell.

• Both have similar things in them: carbohydrates, Both have similar things in them: carbohydrates, proteins, nucleic acids, minerals, fats, and proteins, nucleic acids, minerals, fats, and vitamins.vitamins.

SimilaritiesSimilarities

Some DifferencesSome Differences

• Prokaryotes are OLD!!Prokaryotes are OLD!!– Scientists think they have been around for 3.5 Scientists think they have been around for 3.5

BILLION years! BILLION years! – Scientists say eukaryotes have only been around Scientists say eukaryotes have only been around

for 1.5 billion years.for 1.5 billion years.

• Eukaryotes are much BIGGER!!Eukaryotes are much BIGGER!!– In general, eukaryotes are about 10X bigger than In general, eukaryotes are about 10X bigger than

prokaryotes.prokaryotes.

No membrane bound organellesNo membrane bound organelles Has membrane bound organellesHas membrane bound organelles

Major DifferenceSMajor DifferenceS

Prokaryotic CellProkaryotic Cell Eukaryotic CellEukaryotic Cell

No nucleusNo nucleus Has a nucleusHas a nucleus

Role of the nucleusRole of the nucleus

• Almost all cells contain the genetic information Almost all cells contain the genetic information necessary for the cell (and entire organism—if it’s necessary for the cell (and entire organism—if it’s composed of more than one cell) to survive. This composed of more than one cell) to survive. This genetic information is DNA!genetic information is DNA!– Eukaryotes have separated this information from the Eukaryotes have separated this information from the

rest of the cell with a special membrane bound rest of the cell with a special membrane bound organelle called a nucleus. (Eukaryote means “having organelle called a nucleus. (Eukaryote means “having a true nucleus”.)a true nucleus”.)

– Prokaryotes do NOT have this nucleus and their Prokaryotes do NOT have this nucleus and their genetic material is not separated from the rest of the genetic material is not separated from the rest of the cell. (Prokaryote means “before a nucleus”.)cell. (Prokaryote means “before a nucleus”.)

Today’s ActivityToday’s Activity

• You are going to be building a prokaryotic cell and You are going to be building a prokaryotic cell and comparing your model to a picture of a eukaryotic comparing your model to a picture of a eukaryotic cell. cell.

• Follow the directions to build your model.Follow the directions to build your model.

• After you have built it, you will compare it to the After you have built it, you will compare it to the picture of the eukaryotic cell and list 3 similarities picture of the eukaryotic cell and list 3 similarities and 3 differences between the two cell types.and 3 differences between the two cell types.

Directions• Step 1:

– Use a small piece of tape to tape a rubber band to your cell membrane. This is your cell’s flagella (helps the cell move).

• Step 2:– Use your hand to scoop 2-3 handfuls of Jell-o into your bag.

This is your cell’s cytoplasm (has many nutrients, proteins, minerals and other things in it to keep the cell alive).

• Step 3:– Add a small handful of spaghetti to your bag. This is your cell’s

DNA (codes for all the proteins your cell needs to stay alive).• Step 4:

– Add 10-15 cheerios to your bag. These are your cell’s ribosomes (small structures that make the protein your prokaryotic cell needs to stay alive and do it’s job).

Directions

Use these pictures to answer the questions on your Use these pictures to answer the questions on your worksheetworksheet

Prokaryotic CellProkaryotic Cell Eukaryotic CellEukaryotic Cell