Prokaryotic And Eukaryotic Cells PDF

Prokaryotic and Eukaryotic Cells Unit 2 Lesson 2 Prokaryotic and Eukaryotic Cells Students will be able to: Compare and contrast the cells of prokaryotes and eukaryotes. Key Vocabulary: Capsule, Cell membrane, Cell wall, Circular...

Prokaryotic and Eukaryotic Cells Unit 2 Lesson 2 Prokaryotic and Eukaryotic Cells Students will be able to: Compare and contrast the cells of prokaryotes and eukaryotes. Key Vocabulary: Capsule, Cell membrane, Cell wall, Circular Chromosome, Eukaryote, Membrane-bound organelle, Monera, Multicellular, Nucleus, Organelle, Prokaryote, Unicellular Prokaryotic and Eukaryotic Cells All organisms are made up of microscopic objects called cells. Cells are less than 0.1 mm in diameter and are the smallest units capable of existing and reproducing independently. Cells fall into two distinct categories based on whether they have a well-defined nucleus or not: Prokaryotic and Eukaryotic Cells Prokaryotes Unicellular (single-celled) organisms. The structural features of prokaryotic cells place them in the kingdom Monera. Monera has two domains: Archaea and Bacteria, which is pictured in the lower half of the phylogenetic tree to the right. Prokaryotic and Eukaryotic Cells All other living organisms, e.g. animals, plants, fungi and protists, have eukaryotic cells. They are found in their own kingdom in the upper half of the tree. Prokaryotic and Eukaryotic Cells Comprehension Check Can you... ✓ Define the term cell? ✓ Name two types of cells? ✓ Give the main distinguishing feature between the two types of cells? ✓ Give an example of each type of cell and the kingdom to which they belong? Prokaryotic and Eukaryotic Cells Comprehension Check: Answers 1. Define the term cell? The small unit capable of independent existence and reproduction 2. Name two types of cells? Prokaryote and Eukaryote 3. Give the main distinguishing feature between the two types of cells? Presence of a nucleus (eukaryotes) and its absence (prokaryotes) 4. Give an example of each type of cell and the kingdom to which they belong? Prokaryotes – Bacteria in the kingdom Monera Eukaryotes – Plants in the plant kingdom Prokaryotic and Eukaryotic Cells Prokaryotes Prokaryotic cells range in size from less than 1 micrometer to no more than 10 micrometers. They are much smaller than most eukaryotic cells. The name prokaryote comes from the Scanning electron microscope image of E. coli bacteria, cell size 2 m. Greek, “pro” meaning before and “karyon” meaning nut or kernel, which infers the nucleus of the cell. Prokaryotic and Eukaryotic Cells Key Features of Prokaryotes The diagram of a typical prokaryote (bacteria) is shown to the right. It shows the absence of both a membrane-bound nucleus and other membrane-bound organelles which is a distinguishing feature of all prokaryotic cells. Prokaryotic and Eukaryotic Cells Key Features of Prokaryotes The genetic material or DNA is found free within the cytoplasm of the cell in an irregular region called the nucleoid. The DNA forms a single large coil more commonly known as a circular chromosome. Prokaryotic and Eukaryotic Cells Key Features of Prokaryotes A circular chromosome makes prokaryotic cells highly useful for genetic engineering. Scientists can easily locate, remove and add genetic material Circular DNA under electron microscope to manufacture many useful proteins such as insulin and human growth hormone. Prokaryotic and Eukaryotic Cells Comprehension Check Can you... ✓ Give the size of a prokaryote cell? ✓ Describe the conformation of its DNA? ✓ Give two distinguishing features of this type of cell? Prokaryotic and Eukaryotic Cells Comprehension Check Can you... 1. Give the size of a prokaryote cell? Between 1-10 m 2. Describe the conformation of its DNA? Single circular chromosome 3. Give two distinguishing features of this type of cell? Absence of membrane bound organelles Presence of a capsule or slime layer Prokaryotic and Eukaryotic Cells Eukaryotes Eukaryotes are usually multicellular. Their cells range in size from 10 micrometers to approximately 100 micrometers. The cells of a eukaryotic organism work together and are much more specialized than a prokaryotic cell. Prokaryotic and Eukaryotic Cells Eukaryotes Eukaryotic cells can form much larger structures such as tissues, organs and organ systems. These structures enable the organism to carry out more complex life processes such as circulation and gas exchange more efficiently for their size. Prokaryotic and Eukaryotic Cells Eukaryotes Not all eukaryotes are multicellular. Some forms of algae, slime molds and protozoa exist as unicellular eukaryotic organisms. The diagram to the right shows the structure of the unicellular eukaryote known as Euglena. Prokaryotic and Eukaryotic Cells Comprehension Check Can you... ✓ Define the term multicellular ✓ Give the size of a eukaryote cell? ✓ Give an example of a unicellular eukaryote? Prokaryotic and Eukaryotic Cells Comprehension Check: Answers 1. Define the term multicellular An organism which has more than one cell 2. Give the size of a eukaryote cell? Between 10-100 m 3. Give an example of a unicellular eukaryote? Protozoa, algae, slime molds and euglena Prokaryotic and Eukaryotic Cells Key Features of Eukaryote Cells Eukaryotes have their genetic material in a nucleus. Not surprisingly, the shape of their genetic material differs too. Instead of having a single, circular chromosome, the chromosomes within the nucleus of a eukaryote are linear. Prokaryotic and Eukaryotic Cells Key Features of Eukaryote Cells Eukaryotic cells have many chromosomes with some organisms having well over 100 of these in the nucleus of their body cells. Unlike prokaryotic cells, the chromosomes in a eukaryotic cell become visible when the cell divides. Prokaryotic and Eukaryotic Cells Key Features of Eukaryote Cells Eukaryotic cells also have other TRANSPORT VESICLES organelles which are membrane- bound. Including: MITOCHONDRIA LYSOSOMES GOLGI APPRATUS CHLOROPLASTS VACUOLES ENDOPLASMIC RETICULUM Prokaryotic and Eukaryotic Cells Key Features of Eukaryote Cells These organelles perform specific functions allowing eukaryotic cells to be more specialized. For example, plant cells contain chloroplasts which enables them to carry out photosynthesis. CHLOROPLAST Prokaryotic and Eukaryotic Cells Comprehension Check Can you... ✓ Compare the shape of the prokaryote and eukaryote DNA? ✓ Describe one other difference in the genetic material of a eukaryote compared to prokaryote? ✓ Name three membrane-bound organelles found in eukaryotes? Prokaryotic and Eukaryotic Cells Comprehension Check: Answers 1. Compare the shape of the prokaryote and eukaryote DNA? Prokaryotes have a single circular chromosome while eukaryotes have multiple linear chromosomes 2. Describe one other difference in the genetic material of a eukaryote compared to prokaryote? The DNA becomes visible during cell division in eukaryotes 3. Name three membrane-bound organelles found in eukaryotes? Chloroplasts, nucleus, ribosomes, golgi apparatus, endoplasmic reticulum Vesicles, lysosome, mitochondria Prokaryotic and Eukaryotic Cells Similarities between Prokaryotes and Eukaryotes Although they each have very distinct features, there are some organelles which are common to both prokaryotic and eukaryotic cells. Which organelles are common to both prokaryote and eukaryotes cells? Prokaryotic and Eukaryotic Cells Similarities between Prokaryotes and Eukaryotes Both types of cell have: cytoplasm includes all the cellular content within the cell membrane, excluding the nucleus. ribosomes are non-membrane bound organelles responsible to make a variety of proteins through protein synthesis. plasma membrane (the cell membrane), is the layer that separates the inside and outside of a cell DNA provides the instructions which determines how the cell functions. Prokaryotic and Eukaryotic Cells Differences between Prokaryotes and Eukaryotes Another notable difference between prokaryotes and eukaryotes is the structure of the outermost layer of the cell. Both prokaryotic and eukaryotic cells have a cell membrane. In animal cells and most Protista, this is the only layer which separates the inside and outside environments of the cell. Prokaryotic and Eukaryotic Cells Differences between Prokaryotes and Eukaryotes Prokaryotic cells and other eukaryotic cells, such as plants and fungi have a distinct cell wall. In prokaryotes, this is made of a sugar and amino acid polymer called peptidoglycan, in plants it is a tough polysaccharide called cellulose, and for fungi, it is a glucose polymer called chitin. Cell wall Cell membrane Prokaryotic and Eukaryotic Cells Differences between Prokaryotes and Eukaryotes Prokaryotic cells also have yet another layer which covers their cell wall known as a capsule or slime layer. This layer is vital in many disease-causing bacteria as it allows them to evade the host's immune system and attach it to other objects. Prokaryotic and Eukaryotic Cells Differences between Prokaryotes and Eukaryotes In prokaryotes, the cells undergo asexual reproduction through binary fission or budding to rapidly produce exact replicas. In eukaryotic cells, mitosis is used to produce body cells, while meiosis is used to produce gametic cells such Budding in Yeast cells as sperm, egg and pollen for sexual reproduction. Prokaryotic and Eukaryotic Cells Comprehension Check Can you... ✓ Name the four structures which prokaryotes and eukaryotes have in common? ✓ Explain how the outer layers of eukaryote and prokaryote cells differ? ✓ Name the type of reproduction each type of cell generally uses? Prokaryotic and Eukaryotic Cells Comprehension Check: Answers 1. Name the four structures which prokaryotes and eukaryotes have in common? Cell membrane, ribosomes, cytoplasm, DNA 2. Explain how the outer layers of eukaryote and prokaryote cells differ? Prokaryotes have a cell wall and a capsule over their cell membrane, whereas eukaryotes (animal cells) have only have a cell membrane and plant and fungi cells have a cell wall 3. Name the type of reproduction each type of cell generally uses? Prokaryotes use asexual reproduction while eukaryotes use sexual reproduction Prokaryotic and Eukaryotic Cells In Summary: Features Prokaryotes Eukaryotes Organisms (Five Monera (Bacteria and Animals, Fungi, Plants, Protists Kingdom Classification) Archaea) Level Organization Unicellular (Single-celled) Both unicellular and multicellular Typical cell size 1 μm to 10 μm 10 μm to 100 μm Cell Wall Typically have cell wall Cell wall found on fungi and and capsule plants; Absence of cell wall for animal cells and Protista. Prokaryotic and Eukaryotic Cells In Summary: Features Prokaryotes Eukaryotes Organelles Few organelles present Variety of organelles with specialized functions Genetic material Single circular double stranded Complex chromosomes that DNA; Found in the region called come in pairs and is housed nucleoid. inside the nucleus. Mode of division or (Asexually) - Binary fission and (Sexually/Cell Division) reproduction Budding Mitosis and Meiosis