Cells & Cell Transport. Cells

Transcription

1 Cells & Cell Transport Cells

2 Cell Membrane Cell membrane (plasma membrane): a phospholipid bilayer surrounding the cell Each phospholipid has a polar phosphate head and lipid tails Selectively permeable: allows only certain substance into the cell, like a screen door, only some things can come through

3 Cytoplasm The watery environment of the cell where all cell activity takes place Made up of mostly water, with ions, proteins, and other compounds

4 A network of fibers throughout the cytoplasm called microfilaments and microtubules They provide structure to the cell, points of attachment for organelles (MT), and are used in cell movement (MF) Spindle fibers are used for movement of chromosomes during cell division Cytoskeleton

5 Nucleus Surrounded by a nuclear membrane (nuclear envelope) which is a bilayer like the cell membrane Contains nuclear pores for transport in and out of the nucleus Stores most of the genetic information in the form of chromosomes Directs most activities of the cell.

6 Chromatin Made up of sections of DNA called genes and also proteins Uncurled: chromatin Curled up for transport: chromosomes (these are stained & visible under a microscope) They do not leave the nucleus

7 Nucleolus Found inside the nucleus A mass of RNA, not an official membrane bound organelle like the rest described here Disappears during cell division RNA can leave the nucleus for protein synthesis (ribosome synthesis)

8 (AKA centrosomes) Lay just outside the nucleus, made up of microtubules Involved in cell division (although they are not present in plant cells) Replicate into two centrioles before cell division and migrate to opposite ends of nucleus Centrioles

9 Can be free (in the cytoplasm) or bound (found on the rough ER) Made up of two subunits (large & small), 40% protein & 60% RNA (rrna) The location of protein production (the site of protein synthesis) No membrane Ribosome

10 Endoplasmic Reticulum Can be rough (with ribosomes attached) or smooth (no ribosomes) Two types of ER: Rough ER: transportation of proteins, Smooth ER: toxin breakdown, regulation of calcium and production of steroids when in glad cells (smooth ER) Intracellular highway moves proteins from one part of the cell to another

11 Golgi Apparatus (Body) Responsible for protein processing which includes: *marking proteins with their destination location *preparing proteins to become active and able to do their job (ex: enzyme folding) * Modifies proteins for export System of flattended sacs (pancakes of membrane)

12 Often called the powerhouse of the cell, has a 2 nd inside membrane that folds to increase surface area (cristae, where chemical reactions take place) It generates ATP (cellular energy) from glucose molecules Contains its own DNA unlike every other organelle in the cell Is thought to have once lived on its own Mitochondria

13 Vacuole Used for storage for a variety of things including food, waste, and proteins to be transported out/around the cell A moving vacuole is called a vesicle Plants have a large central vacuole for water storage to keep the shape of the plant cell

14 A small, spherical vacuole containing digestive enzymes They fuse with vacuoles containing substances to be broken down (food, waste, invading bacteria) Digest protein, carbs, lipids, DNA, RNA and sometimes old organelles, viruses, bacteria that the cells ingested Rare in plant cells Lysosome

15 Found in bacteria, fungus, plant, and some protists Made up of cellulose in plant cells Adds extra security/protection and/or provides structure (shape) for cells Cell Wall

16 Flagella and Cilia Used for movement in some protist and animal cells, made of microtubules Flagella are whip like tails (one or more) for movement much like a tail is used for swimming by fish Cilia are hair like extensions (circular movement is like that of a bullet) Video comparing flagella and cilia movement: m/watch?v=qgam6h MysTA

17 Chloroplasts Contain chlorophyll (green, yellow, red color) Only found in cells that do photosynthesis (plants, some protists, some bacteria) Like mitochondria, they contain their own DNA and are thought to have lived as single celled organisms at one time

18 Plant vs. Animal Cells No centrioles for cell division A large central vacuole Cell wall of cellulose to help maintain square shape Chloroplasts containing chlorophyll for photosynthesis Use centrioles for cell division No central vacuole No cell wall No chloroplasts, no chlorophyll, no photosynthesis