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Eukaryotic Cell

Eukaryotic Cell

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Eukaryotic Cell

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  1. Eukaryotic Cell • Eukaryotic means “true nucleus”

  2. Endosymbiotic Hypothesis Biologist Lynn Margulis has suggested that mitochondria and chloroplasts are descendants of ancient prokaryotes.

  3. Mitochondria and chloroplasts were once free living prokaryotes that were engulfed by Amoeba-like Eukaryotic cells

  4. Same size and shape as bacteria • Double membrane • 70 S Ribosomes • Circular chromosomes • Replicate on their own

  5. 4

  6. Plant Cells Have • Cell Wall • E.R. • Chloroplast

  7. Animal Cells Contain • Lysosomes • Mitochondria • E.R.

  8. Animal Cell

  9. Eukaryotic Example

  10. Plant Cell

  11. Parts of the Eukaryotic Cell

  12. Cell Wall • Extra structure surrounding its plasma membrane in plants, algae, fungi, and bacteria. • Cellulose – Plants • Chitin – Fungi • Peptidoglycan - Bacteria

  13. Cell Wall Rigidity helps support and protect the plant cell

  14. Plant Cells with Cell Wall

  15. Cell Membrane

  16. Cell Wall

  17. Cell membrane • The Plasma membrane • The boundary of the cell. • Composed of three distinct layers. • Two layers of fat and one layer of protein.

  18. Cell Membrane

  19. Selectively Permeable • Only certain things can enter / exit the cell • Thin, flexible barrier around a cell, selectively permeable

  20. STRUCTURE Made up 45% protein & 45% phospholipids with the remaining 10% cholesterol, glycoprotein & glyolipids FUNCTION Forms a recognition site so that the body’s immune system can recognize its own cells Acts as a receptor site for the attachment of specific hormones and neurotransmitters. Plasma (cell surface) membrane

  21. Cytoplasm Contains the organelles of the cell

  22. Cytoplasm

  23. Cytoplasm Structure • The entire region of the cell between the nucleus and the cell membrane • Consists of various organelles suspended in a fluid • Clear, thick, jellylike material

  24. Cytoplasm Function • Provides a cushiony watery home for the cell organelles that carry out the functions of the cell • Supports and protects organelles.

  25. What is an organelle? It is a structure in eukaryotic cells that acts as if it is a specialized organ.

  26. Chloroplast used to trap energy of sunlight during photosynthesis with chlorophyll & convert to energy

  27. Chloroplast

  28. Chloroplasts • Contain small DNA and 70s ribosomes • Stroma thick fluid in center • Generation of ATP & sugars

  29. Chloroplasts • Flat discs 2-10 um in diameter & 1um thick • Inner membrane folded into a series of lamellae • Inside the membrane is a fluid – stroma – which contains the enzymes involved in photostnthesis • Small amounts of DNA and oil are found in the stroma

  30. Chloroplasts • In stroma is a network of flattened sacs called thylakoids • Grana (granum) are formed when many thylakoids are stacked together (like a pile of coins) (thylakoids also called lamellae) • Chlorophyll molecules are attached to the thylakoids

  31. 70 S Ribosomes • Circular chromosomes • Replicate on their own

  32. Chloroplasts

  33. Chloroplasts Structure and Function • Contain stacked membranes, green, oval • Responsible for photosynthesis • Capture energy from sunlight and use it to produce food for the cell.

  34. The Chloroplast • Double membrane • Center section contains grana • Thylakoid (coins) make up the grana. • Stroma - gel-like material surrounding grana • Found in plants and algae.

  35. Vacuoles • What are vacuoles? • Fluid filled organelle that stores enzymes, metabolic wastes, salt, proteins, carbohydrates and water.

  36. The Vacuole • Saclike structure that stores materials • Sacs that help in food digestion or helping the cell maintain its water balance. • Found mostly in plants and protists.

  37. Vacuoles Structure and Function • Structure - Plants have one large, called a central vacuole. Animal cells have many small circular ones. • Function- Contain water and storage materials

  38. Central Vacuole • What is the role of the central vacuole in plants? • When the central vacuole is filled with liquid, the pressure within the vacuole supports the heavy structures of the plant, such as leaves and flowers.

  39. Vacuole (in a plant cell)

  40. Vacuole

  41. Most nuclei contain a small, dense region known as the • nucleolus

  42. The Nucleus • Brain of Cell • Bordered by a porous membrane - nuclear envelope. • Contains granular thin fibers of DNA and protein called Chromatin. • Rod Shaped Chromosomes • Contains a small round nucleolus • produces ribosomal RNA which makes ribosomes.

  43. Nucleus • Largest structure in cell • Nucleoli Site where ribosomes are made • DNA associated with proteins - histones

  44. Nucleus Function • Contains the cell’s DNA • Directs all the activities of the cell “the Brain” • Pores allow for specific communication with the cytoplasm

  45. Chromatin • Structure - The thin material visible within the nucleus is called Chromatin Function – Contain genetic material (DNA) which hold the instructions for directing the cell’s functions.

  46. What are chromosomes? • They are distinct, threadlike structures formed of condensed chromatin that contain genetic information that is passed from one generation of cells to the next.

  47. 5 Eukaryotic DNA • DNA packaged in a chromosome • Linear DNA • Associated proteins