1 / 17

Exploring Cell Structure and Transport Mechanisms

Learn about cell structure, membrane functions, transport mechanisms, types of cells, and cellular environments. Discover the differences between prokaryotic and eukaryotic cells and their organelles.

raysoto
Télécharger la présentation

Exploring Cell Structure and Transport Mechanisms

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 and Function

  2. The Cell Theory • All living things are made of one or more cells • All cells come from pre-existing cells • Cells are the basic unit for structure and function of all organisms

  3. Cell structure • All cells are surrounded by a plasma (cell) membrane • Cells contain organelles - small structures inside cells that perform various jobs • All cells can be divided into two main categories:

  4. Prokaryotic no nucleus Very small (1-10 um) Have very few organelles Eukaryotic have a nucleus Larger 10-100um (some larger) Have many organelles Prokaryotic vs. Eukaryotic Cells

  5. Eukaryotic Cells • Plant and animal cells are eukaryotic as well fungi and protists (amoeba, paramecium, etc) • Plant and animal cells have important differences (see diagrams)

  6. Eukaryotic Cellular Organization • Single celled organisms (unicellular) • Multiple celled organisms (multicellular) - in multicellular organisms, cells become specialized (do a particular job)

  7. Plasma (cell) membrane • Consists of a double layer of lipids • The outside and inside of the membrane is hydrophilic (“water-loving”) • The interior of the membrane is hydrophobic (“water-fearing”) • Substances must cross the membrane to enter and exit the cell

  8. Types of Membrane Transport Passive Transport (requires NO energy) • Moves substances from a high to a low concentration • Diffusion & osmosis, facilitated diffusion Active Transport (requires energy) • Substances move from a low to a high concentration • Endocytosis & exocytosis

  9. Concentration gradient • Passive transport moves substances WITH (or DOWN) their concentration gradient • Active Transport moves substances AGAINST their concentration gradients PASSIVE TRANSPORT HIGH LOW ACTIVE TRANSPORT

  10. Diffusion • Movement of a substance from a high concentration to a low concentration

  11. Osmosis • Movement of water from a high water concentration to a low water concentration

  12. Osmosis in Different Cellular Environments • Hypotonic - solution with a lower solute concentration than the cytoplasm of the cell • Hypertonic - solution with a higher solute concentration than the cytoplasm of the cell • Isotonic - has same solute concentration as the cytoplasm of the cell

  13. Turgor pressure - pressure (from water) pushing against the cell wall of a plant (makes plant cells firm) • Plasmolysis - shrinking of the cytoplasm of a cell caused by the loss of water (causes plants to wilt)

  14. Facilitated Diffusion • Diffusion using membrane protein channels • Some substance must use protein channels since they cannot pass through the lipid layer of the membrane

  15. Active Transport • Requires the input of energy to move a substance against its concentration gradient (low to high) • Energy is used in the form of ATP (energy molecule produced in mitochondria)

  16. Types of Active Transport: Endocytosis, Exocytosis and Ion Pumps • Endocytosis - cell takes in substances too large to pass through the membrane • Exocytosis - cell gets rid of large substances • Ion pumps - pump ions against their concentration gradient See endocytosis and exocytosis in action

More Related