Prokaryotic Cells Vs. Eukaryotic Cells

Now that we have learned how living things are organized what’s next? We will learn more about the lowest level of organization: cells We will learn more about the lowest level of organization: cells What is the first thing that we need to know about cells? All cells fall into one of the two major classifications of either prokaryotic or eukaryotic. All cells fall into one of the two major classifications of either prokaryotic or eukaryotic.

What’s the difference between prokaryotes and eukaryotes? Prokaryotic cells were here first and for billions of years were the only form of life on Earth. All prokaryotic organisms are unicellular Prokaryotic cells were here first and for billions of years were the only form of life on Earth. All prokaryotic organisms are unicellular Eukaryotic cells appeared on earth long after prokaryotic cells but they are much more advanced. Eukaryotic organisms unlike prokaryotic can be unicellular or multicellular. Eukaryotic cells appeared on earth long after prokaryotic cells but they are much more advanced. Eukaryotic organisms unlike prokaryotic can be unicellular or multicellular.

Glow in the dark squid… how does it do that?

Vibrio fischeri Vibrio fischeri Glow in the dark bacteria Glow in the dark bacteria Helps it survive in the ocean Helps it survive in the ocean Lives in fish and other marine life Lives in fish and other marine life

Let’s Take a Look at the Characteristics of Prokaryotes Prokaryotes are the simplest type of cell. Prokaryotes are the simplest type of cell. Oldest type of cell appeared about four billion years ago. Oldest type of cell appeared about four billion years ago. Prokaryotes are the largest group of organisms Prokaryotes are the largest group of organisms Prokaryotes unicellular organisms that are found in all environments. Prokaryotes unicellular organisms that are found in all environments.

Let’s Take a Look at the Characteristics of Prokaryotes Prokaryotes do not have a nuclear membrane. Their circular shaped genetic material dispersed throughout cytoplasm. Prokaryotes do not have a nuclear membrane. Their circular shaped genetic material dispersed throughout cytoplasm. Prokaryotes do not have membrane-bound organelles. Prokaryotes do not have membrane-bound organelles. Prokaryotes have a simple internal structure. Prokaryotes have a simple internal structure. Prokaryotes are smaller in size when compared to Eukaryotes. Prokaryotes are smaller in size when compared to Eukaryotes.

Shapes of Prokaryotes Cocci = spherical (round) Cocci = spherical (round) Bacillus = (rod shaped) Bacillus = (rod shaped) Spirilla = helical (spiral) Spirilla = helical (spiral)

What do prokaryotic cell look like?

Now let’s take a look at the characteristics of eukaryotes Eukaryotic cells appeared approximately one billion years ago Eukaryotic cells appeared approximately one billion years ago Eukaryotes are generally more advanced than prokaryotes Eukaryotes are generally more advanced than prokaryotes Nuclear membrane surrounds linear genetic material (DNA) Nuclear membrane surrounds linear genetic material (DNA)

Is there more? Yes!!! Unlike prokaryotes, eukaryotes have several different parts. Unlike prokaryotes, eukaryotes have several different parts. Eukaryote’s organelles have coverings known as membranes. Eukaryote’s organelles have coverings known as membranes. Eukaryotes have a complex internal structure. Eukaryotes have a complex internal structure. Eukaryotes are larger than prokaryotes in size. Eukaryotes are larger than prokaryotes in size.

What do eukaryotic cells look like? Mitochondria Nucleus Golgi Complex Endoplasmic Reticulum Cell Membrane Cytoplasm

How do the differences line up? Prokaryotes Organelles lack a membrane Organelles lack a membrane Ribosomes are the only organelles Ribosomes are the only organelles Genetic material floats in the cytoplasm (DNA and RNA) Genetic material floats in the cytoplasm (DNA and RNA)Eukaryotes Organelles covered by a membrane Organelles covered by a membrane Multiple organelles including ribosomes Multiple organelles including ribosomes Membrane covered Genetic material Membrane covered Genetic material

How do the differences line up? Prokaryotes Circular DNA Circular DNA Unicellular Unicellular Cells are smaller in size Cells are smaller in size Has larger number of organisms Has larger number of organismsEukaryotes Linear DNA Linear DNA May be multicellular or unicellular May be multicellular or unicellular Cells are larger in size Cells are larger in size Has smaller number of organisms Has smaller number of organisms

How do the differences line up? Prokaryotes Appeared 4 billion years ago Appeared 4 billion years agoEukaryotes Appeared 1 billion years ago Appeared 1 billion years ago

How do the similarities line up? Lets See!!! Both types of cells have cell membranes (outer covering of the cell) Both types of cells have cell membranes (outer covering of the cell) Both types of cells have ribosomes Both types of cells have ribosomes Both types of cells have DNA Both types of cells have DNA Both types of cells have a liquid environment known as the cytoplasm Both types of cells have a liquid environment known as the cytoplasm

Your turn: Make a Venn Diagram outlining the similarities and differences between prokaryotes and eukaryotes Make a Venn Diagram outlining the similarities and differences between prokaryotes and eukaryotes You may use your book and/or consult your teammate You may use your book and/or consult your teammate

Robert Hooke Used a compound microscope and viewed a slice of cork. Used a compound microscope and viewed a slice of cork. He saw little box structures and called them cells. He used this name because it reminded him of little rooms that monks lived in. He saw little box structures and called them cells. He used this name because it reminded him of little rooms that monks lived in.

Anton Van Leeuwenhoek Was the first to see living organisms and called them animalcules. Was the first to see living organisms and called them animalcules. Used the first simple light microscope. Used the first simple light microscope.

Matthias Schleiden First to see living plant cells and determined that plants are also made of these tiny structures called cells. First to see living plant cells and determined that plants are also made of these tiny structures called cells.

Theodor Schwann Viewed animal tissue and concluded that animals are also made of these tiny structures called cells. Viewed animal tissue and concluded that animals are also made of these tiny structures called cells.

Rudolf Virchow He was the scientist that said cells can only be produced by other living cells. He was the scientist that said cells can only be produced by other living cells.

The Cell Theory 1. All Organisms are composed of one or more cells. 2. The cell is the basic unit of structure and organization of organisms. 3. All cells come from other living cells.

Cells

Organelles are membrane-bound cell parts Mini “organs” that have unique structures and functions Mini “organs” that have unique structures and functions Located in cytoplasm Located in cytoplasm

Cell membrane Cell membrane delicate lipid and protein skin around cytoplasm delicate lipid and protein skin around cytoplasm found in all cells found in all cells Cell Structures

Nucleus Nucleus a membrane-bound sac evolved to store the cell’s chromosomes(DNA) a membrane-bound sac evolved to store the cell’s chromosomes(DNA) has pores: holes has pores: holes

Nucleolus Nucleolus inside nucleus inside nucleus location of ribosome factory location of ribosome factory made or RNA made or RNA

mitochondrion mitochondrion makes the cell’s energy makes the cell’s energy the more energy the cell needs, the more mitochondria it has the more energy the cell needs, the more mitochondria it has

Ribosomes Ribosomes build proteins from amino acids in cytoplasm build proteins from amino acids in cytoplasm may be free-floating, or may be free-floating, or may be attached to ER may be attached to ER made of RNA made of RNA

Endoplasmic reticulum Endoplasmic reticulum may be smooth: builds lipids and carbohydrates may be smooth: builds lipids and carbohydrates may be rough: stores proteins made by attached ribosomes may be rough: stores proteins made by attached ribosomes

Golgi Complex Golgi Complex takes in sacs of raw material from ER takes in sacs of raw material from ER sends out sacs containing finished cell products sends out sacs containing finished cell products

Lysosomes Lysosomes sacs filled with digestive enzymes sacs filled with digestive enzymes digest worn out cell parts digest worn out cell parts digest food absorbed by cell digest food absorbed by cell

Centrioles Centrioles pair of bundled tubes pair of bundled tubes organize cell division organize cell division

Cytoskeleton made of microtubules made of microtubules found throughout cytoplasm found throughout cytoplasm gives shape to cell & moves organelles around inside. gives shape to cell & moves organelles around inside.

Structures found in plant cells Cell wall Cell wall very strong very strong made of cellulose made of cellulose protects cell from rupturing protects cell from rupturing glued to other cells next door glued to other cells next door

Vacuole Vacuole huge water-filled sac huge water-filled sac keeps cell pressurized keeps cell pressurized stores starch stores starch

Chloroplasts Chloroplasts filled with chlorophyll filled with chlorophyll turn solar energy into food energy turn solar energy into food energy

How are plant and animal cells different?

StructureAnimal cellsPlant cells cell membraneYesyes nucleusYesyes nucleolusyes ribosomesyes ERyes Golgiyes centriolesyesno cell wallnoyes mitochondriayes cholorplastsnoyes One big vacuolenoyes cytoskeletonyesYes

Eukaryote cells can be multicellular The whole cell can be specialized for one job The whole cell can be specialized for one job cells can work together as tissues cells can work together as tissues Tissues can work together as organs Tissues can work together as organs

Advantages of each kind of cell architecture ProkaryotesEukaryotes simple and easy to growcan specialize fast reproductionmulticellularity all the samecan build large bodies

What do all these have in common?

Specialized Cells 1. All must be able to describe with examples, how cells are specialised to perform different functions. 2. Most should be able to state how cells group together to form tissues. 3. Some could state how specific cells are adapted to their function. 1. What is the picture? 2. Discuss what is a specialised cell 3. Powerpoint showing different specialised cells 4. Worksheet 5. Quiz on plant and animal cells Learning Objectives: Learning Activities:

W HAT IS A SPECIALIZED C ELL ? Plants and animals consist of many cells and so are known as multicellular They contain many different types of cells. Each type of cell is designed to carry out a particular job or function. This is known as cell specialism Not all cells look the same. Some cells have a special shape and features to help them do a certain job.

S PERM CELL The head contains enzymes which allow it to digest into an egg cell and join with it. Head contains enzymes & nucleus Tail Designed to Fertilise eggs. A sperm is small and has a long tail that provides movement so it can swim and find an egg cell. Found in the Testes

E GG (O VUM ) C ELL Designed to be Fertilised. Found in the Ovaries. An egg cell is large and bulky. Contains yolk which provides a large food store for the new cell being formed. Cytoplasm containing yolk Layer of jelly Nucleus

P ALISADE C ELL Designed for Photosynthesis Found in the top of a leaf Tall and has a large surface area to absorb water and minerals. Packed with chloroplasts to help make plant food. Nucleus Chloroplasts

C ILIATED C ELL Designed to stop Lung Damage They line all the air passages (trachea, bronchi & bronchioles) in the lungs. They have tiny hairs called cilia. Hairs sweep mucus with trapped dust and bacteria back up the throat. Nucleus cilia

R OOT H AIR C ELL Designed for absorbing. Thin cell wall makes it easy for minerals to pass through. Has a large surface which helps it to absorb water and minerals. Found in a plant root. Vacuole Cell membrane thin cell wall

N ERVE C ELL ( NEURONE ) They are long They have connections at each end Can carry electrical signals Their job is to carry nerve impulses to different parts of the body. Nucleus

R ED B LOOD C ELL Designed to carry oxygen Found in blood. Large surface area, for oxygen to pass through. Contains haemoglobin, which joins with oxygen. Has no nucleus

How do animal cells move? Some can crawl with pseudopods Some can crawl with pseudopods Some can swim with a flagellum Some can swim with a flagellum Some can swim very fast with cilia Some can swim very fast with cilia

Pseudopods means “fake feet” means “fake feet” extensions of cell membrane extensions of cell membrane example: ameoba example: ameoba

Flagellum/flagella large whiplike tail large whiplike tail pushes or pulls cell through water pushes or pulls cell through water can be single, or a pair can be single, or a pair

Cilia fine, hairlike extensions fine, hairlike extensions attached to cell membrane attached to cell membrane beat in unison beat in unison