1 / 24

Cell structure, genetic control, and life cycle

Cell structure, genetic control, and life cycle. Movement of molecules into cells. Through membrane Phagocytosis Endocytosis/pinocytosis Exocytosis/secretion. Receptor-mediated endocytosis. Projections on cell surface Cilia made from microtubules move in “beating” pattern

ariane
Download Presentation

Cell structure, genetic control, and life cycle

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cell structure, genetic control, and life cycle

  2. Movement of molecules into cells • Through membrane • Phagocytosis • Endocytosis/pinocytosis • Exocytosis/secretion

  3. Receptor-mediated endocytosis

  4. Projections on cell surface Cilia made from microtubules move in “beating” pattern Lumen side of respiratory and female reproductive tract Flagella- also made of microtubules whiplike movement only on sperm cells in humans

  5. Microvilli fingerlike projections of cell membrane lumen (apical) side of cell Aid in absorption (increase surface area of membrane)

  6. The cytoskeleton microtubules Organelles are not just floating around!

  7. Lysosomes degrade large molecules double membrane hydrolytic enzymes Peroxisomes found in liver and kidney cells toxic by-products of oxygen produced by reactions with these enzymes Catalase- converts these to harmless forms

  8. Structure of a mitochondrion; note inner and outer membranes

  9. Mitochondrion Production of ATP Many metabolic disorders associated with defective enzymes in mitochondria

  10. Protein synthesis and endomembrane system • Complex system required for protein synthesis • Ribosomes • Rough endoplasmic reticulum (rough ER) • Golgi (complex, apparatus)

  11. Endoplasmic reticulum • Rough ER is covered with ribosomes • Protein processing begins • Smooth ER: lipid synthesis, calcium storage- tissue specific

  12. Endoplasmic reticulum Rough (granular)- overed with ribosomes protein synthesis, processing glycosylation some cells have more of this than others Smooth lipid synthesis (steroid hormones) calcium storage

  13. Golgi: where does the protein go?

  14. Nucleus contains genetic information • DNA contained in chromosomes • RNA formed but transported out of nucleus • Pores control access

  15. Chromatin can be “opened up” by acetylation Levels of structure in chromatin

  16. Protein synthesis is dictated by DNA Messenger RNA is transcribed (copied) from DNA. mRNA can move into cytoplasm mRNA is a template from which amino acid chains (polypeptides) are built Ribosomes Transfer RNA Amino acids

  17. Formation of messenger RNA • Genes are transcribed off a single strand of DNA • 25,000 genes can yield over 100,000 proteins • Regulated through RNA interference

  18. Messenger RNA is “translated” into protein (but this is only the first step in protein synthesis)

  19. Protein is assembled in the endomembrane system • Polypeptide forms secondary, tertiary, quaternary structure • May be modified by carbohydrates or lipids • Chaperones help proteins fold correctly

  20. The life cycle of a cell

  21. How is the cell cycle controlled? Proto-oncogenes allow cell to proceed through cell cycle Tumor suppressor genes prevent cell from going to the next stage of the cell cycle Mutations in these genes interfere with control of growthcancer Apoptosis- “programmed cell death”

  22. Review mitosis and meiosis • What types of cells undergo mitosis and meiosis- and when? • What are the products of mitosis and meiosis? • What are the implications for inheritance? • Gene expression can vary in cells

  23. Summary • The work of a cell is organized into organelles • Genetic information is contained in DNA, and is expressed through transcription and translation • In cell division, DNA is copied and distributed into new cells • Regulation of these activities varies at different times and in different cells

More Related