Slide 1 / 143 Slide 2 / 143 Eukaryotes January 2014 www.njctl.org Slide 3 / 143 Vocabulary Click on each word below to go to the definition. 5' cap exocytosis adhering junction exon alternative splicing extracellular matrix cell junction food vacuole central vacuole fungi chitin gap junction chloroplast glycoprotein chromatin golgi appartus chromatin modifying enzyme histone hydrolytic enzyme contractile vacuole intermediate filament cytoskeleton endocytosis intermembrane space intron endomembrane system endosymbiosis lumen eukaryote lysosome
Slide 4 / 143 Vocabulary Click on each word below to go to the definition. matrix poly-A tail microfilament pre-mRNA microtubule protist mitochondrion receptor-mediated endocytosis mRNA processing RNA splicing nuclear envelope rough endoplasmic reticulum nuclear pore smooth endoplasmic reticulum nucleolus stroma nucleosome tight junction nucleus transcription factor organelle transport vesicle peroxisome turgor pressure phagocytosis pinocytosis plasmodesmata Slide 5 / 143 Eukaryotes Unit Topics Click on the topic to go to that section · The Eukaryotic Cell · The Nucleus & Gene Expression · The Endomembrane System · Energy-Converting Organelles · Other Organelles & Cell Structures Slide 6 / 143 The Eukaryotic Cell Return to Table of Contents
Slide 7 / 143 All Cells All cells have 4 things in common. · They are surrounded by a plasma membrane (or cell membrane). · They contain a semifluid substance called the cytosol/ cytoplasm . · They contain structures called chromosomes , which carry the cell's genes. · They have ribosomes, which assemble amino acids into proteins. Slide 8 / 143 Eukaryotes vs. Prokaryotes There are 3 key differences between prokaryotic and eukaryotic cells. · Eukaryotic cells are usually larger than prokaryotic cells. · Eukaryotic cells have small compartments inside them call organelles . · Most eukaryotes (but not all) are multi-cellular organisms. Slide 9 / 143 1 Which is NOT a basic feature of all cells? A All cells are surrounded by a plasma membrane. B Al cells contain a semifluid substance called the cytoplasm. All cells contain structures called chromosomes, which are contained in C the nucleus. D All cells have ribosomes.
Slide 9 (Answer) / 143 1 Which is NOT a basic feature of all cells? A All cells are surrounded by a plasma membrane. B Al cells contain a semifluid substance called the cytoplasm. All cells contain structures called chromosomes, which are contained in C the nucleus. D All cells have ribosomes. Answer C [This object is a pull tab] Slide 10 / 143 Cell Size Eukaryotic cells are, on average, much larger than prokaryotic cells. The average diameter of most prokaryotic cells is between 1 and 10 µm. By contrast, most eukaryotic cells are between 5 to 100 µm in diameter. Animal Cell (Eukaryote) Bacterium (Prokaryote) Slide 11 / 143 Surface Area to Volume Ratio At the time when prokaryotic cells were evolving, there were most likely different sizes of cells. A cell's efficiency and ability to survive depended on its surface area to volume ratio . The volume of the cell determines the amount of chemical activity it can carry out per unit time. The surface area of the cell determines the amount of substances the cell can take in from the environment and the amount of waste it can release. As a cell grows in size, it's surface area to volume ratio decreases. It performs chemical reactions faster, but it has a harder time getting nutrients in and waste out.
Slide 12 / 143 Limits of Cell Size We know that cells need to be small enough so that they have an increased surface area to volume ratio, but be large enough to perform the chemical reactions of metabolism. Least Efficient Most Efficient The smaller the cell, the larger The bigger the cell, the smaller its surface area and the smaller the surface area is compared its volume. to its large volume inside. Slide 13 / 143 Organelles To increase efficiency in the larger cell, eukaryotes evolved many bacterium-sized parts known as organelles . Organelles subdivide the cell into specialized compartments. They play many important roles in the cell. Some transport waste to the cell membrane. Others keep the molecules required for specific chemical reactions located within a certain compartment so they do not need to diffuse long distances to be useful. Slide 14 / 143 Organelles Organelles making up Eukaryotic cells include: · Nucleus · Vacuoles · Lysosomes · Smooth Endoplasmic Reticulum · Ribosomes · Rough Endoplasmic Reticulum · Peroxisomes · Chloroplasts · Mitochondria · Golgi Apparatus
Slide 15 / 143 Multicellular Organisms Even with organelles, the size of the cell is limited to about 1000 µm 3 . This is why large organisms must consist of many smaller cells. Slide 16 / 143 Diversity of Eukaryotes Protists: The first eukaryotic cells. Protists are single-celled eukaryotes. They range from protozoans to algae. Fungi: These organisms evolved second in time along with plants. Examples include mushrooms, molds, and mildews. Plants: Plants vary in type from the first plants called mosses to the modern flowering plants. Animals : Animals were the last eukaryotes to evolve. Animals range from ancient sponges and hydra to primates. Slide 17 / 143 2 Which of the following are prokaryotic cells? A Plants B Fungi C Bacteria D Animals
Slide 17 (Answer) / 143 2 Which of the following are prokaryotic cells? A Plants B Fungi Answer C Bacteria C D Animals [This object is a pull tab] Slide 18 / 143 3 How did eukaryotes solve the problem of small surface area to volume ratio? A by remaining the same size as prokaryotes B by becoming multicellular organisms C by compartmentalizing functions into organelles D they haven't solved the problem Slide 18 (Answer) / 143 3 How did eukaryotes solve the problem of small surface area to volume ratio? A by remaining the same size as prokaryotes B by becoming multicellular organisms Answer C by compartmentalizing functions into organelles C D they haven't solved the problem [This object is a pull tab]
Slide 19 / 143 4 All eukaryotes are multi-cellular. True False Slide 19 (Answer) / 143 4 All eukaryotes are multi-cellular. True False Answer False [This object is a pull tab] Slide 20 / 143 The Nucleus & Gene Expression Return to Table of Contents
Slide 21 / 143 The Nucleus The defining organelle in eukaryotic cell is the nucleus . The nucleus of the cell contains the DNA and controls the cell's activities by directing protein synthesis from DNA. prokaryotes : pro: before karyon: kernel/seed (nucleus) eukaryote : eu: true karyon: kernel/seed (nucleus) So prokaryote = "before a nucleus" And eukaryote = "true nucleus" Slide 22 / 143 The Biological Nucleus The nucleus from chemistry with protons and neutrons is not the same nucleus involved with cells. Biological Nucleus The biological nucleus is usually, but not always, in the center of a cell and it is sometimes referred to as the "control center" of the cell. Slide 23 / 143 Inside the Nucleus The nucleus is enclosed by a double cell membrane structure called the nuclear envelope. The nuclear envelope has many openings called nuclear pores. Nuclear pores help the nucleus "communicate" with other parts of the cell. Inside the nucleus is a dense region known as the nucleolus . The nucleolus is where rRNA is made and ribosomes are assembled. They then exit through the nuclear pores.
Slide 24 / 143 3 Main Functions of the Nucleus 1. To keep and contain a safe copy of all chromosomes (DNA) and pass them on to daughter cells in cell division. 2. To assemble ribosomes (specifically in the nucleolus). 3. To copy DNA instructions into RNA (via transcription). Slide 25 / 143 5 Cells that contain a "true nucleus" and other membrane bound organelles are _______________. A archaea. B bacteria. C eukaryotes. D prokaryotes. Slide 25 (Answer) / 143 5 Cells that contain a "true nucleus" and other membrane bound organelles are _______________. A archaea. B bacteria. Answer C C eukaryotes. D prokaryotes. [This object is a pull tab]
Slide 26 / 143 6 Where is the DNA of a eukaryote found? A Nucleus B Nucleolus C Nucleoid D Mitochondria Slide 26 (Answer) / 143 6 Where is the DNA of a eukaryote found? A Nucleus B Nucleolus Answer C Nucleoid A D Mitochondria [This object is a pull tab] Slide 27 / 143 7 How does the nucleus control the activities of the cell? A By making DNA. B By directing protein synthesis. C By allowing DNA to leave the nucleus to make proteins. D By sending instructions to the mitochondria.
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