Presentation is loading. Please wait.

Presentation is loading. Please wait.

The cell Cell theory: All living things contain cells. All cells come from other cells.

Similar presentations


Presentation on theme: "The cell Cell theory: All living things contain cells. All cells come from other cells."— Presentation transcript:

1 The cell Cell theory: All living things contain cells. All cells come from other cells.

2 Viruses Are viruses living? Influenza virus (an Orthomyxovirus) According to cell theory no. However they do contain organic molecules (DNA or RNA & protein) and can replicate themselves using a host cell, so some biologists say yes. This demonstrates the rule, that for every rule in biology, we can usually find at least 1 exception

3 Prokaryotic cells Do they have a nucleus? Do they have organelles? How big are they? Examples include Escherichia coli bacteria Streptococcus pnemoniae no Very small - usually 1 – 10  m no Bacteria, blue green bacteria

4 Eukaryotic cells Do they have a nucleus? Do they have organelles? How big are they? Examples include yes Larger than bacteria – usually 20 – 500  m Plants, animals, fungi, Protista

5 Cell membrane Main function Controls entry and exit of substances

6 Cell wall Main function Provides structure and support Only found in plant cells

7 Cytoplasm Main function Provides a medium for reactions & site for organelles

8 Nucleus Main function Control centre – contains the genetic blueprint (genes) for coding proteins, hence controls all cell activities

9 Nucleolus Main function Site of RNA production & storage

10 Nuclear membrane Main function Keeps DNA within nucleus

11 Endoplasmic reticulum Main function Transport system, site for reactions to occur

12 Ribosomes Main function Site of protein synthesis Some are found free in the cytoplasm Most are found attached to the endoplasmic reticulum

13 Mitochondria Main function Site of aerobic respiration – energy production

14 Plastids

15 Chloroplasts Main function Site of photosynthesis Only found in plant cells

16 Golgi body Main function Packaging for secretion

17 Vacuoles Main function Storage of food and water In plants provides strength and structure to cell Plant cells usually have 1 large one Animal cells usually have several smaller ones

18 Lysosomes Main function Storage of wastes Most contain enzymes that break down substances

19 Contractile vacuole Main function Pumps out excess water, hence maintaining water balance in the cell Only found in some unicellular organisms

20 Centrioles Main function Forms spindle during cell division Only found in animal cells

21 Cytoskeleton Microfilaments are thin fibres that are made mostly of the protein actin. Microfilament fibres can change length when supplied with energy by ATP, and so they allow cells to change shape. They also guide the movements of organelles within the cell. Interactions of actin and the protein myosin are important in contraction of muscle cells. Intermediate fibres (intermediate filaments) are somewhat larger in diameter than are microfilaments, and are made of several different proteins. Intermediate fibres form a 3-D network throughout the cell that forms much of the framework of the cell and holds the organelles in position. Microtubules are about 24 nanometers in diameter, somewhat thicker than microfilaments or intermediate fibres. Microtubules are hollow and composed largely of the protein tubulin. Microtubules help to position, anchor, and move organelles. They are also important in cellular reproduction and in the movements of cells. Microtubules are important components of both cilia and flagella, and of centrioles.

22 Cilia and flagella Main function Usually found in animal or Protist cells Movement

23 Plant cells Special features include: Cell wall Chloroplasts Large single vacuole No centrioles

24 Animal cells Special features include: No cell wall No chloroplasts Vacuoles usually small and numerous Centrioles

25 What type of cell am I?

26 plant animal Prokaryotic

27 What type of cell am I?

28 animal plant

29 Label the cells

30 Cell wall Cell membrane Cell membrane nucleus nucleolus Nuclear membrane Nuclear membrane Chromatin/DNA mitochondrion cytoplasm lysosome chloroplast centrioles Golgi body vacuole Rough endoplasmic reticulum cytoplasm Smooth endoplasmic reticulum Rough endoplasmic reticulum ribosomes vacuole Smooth endoplasmic reticulum

31 Identify the organelles

32 Cell wall nucleus mitochondrion nucleolus vacuole Nuclear membrane cytoplasm chloroplast Rough endoplasmic reticulum Nuclear pore

33 Identify the function of these cell membrane cell wall cytoplasm nucleus nucleolus nuclear membrane mitochondria Golgi body Provides a medium for reactions & site for organelles Controls entry and exit of substances Provides structure and support Control centre – contains the genetic blueprint (genes) for coding proteins, hence controls all cell activities Site of RNA production & storage Keeps DNA within nucleus Site of aerobic respiration – energy production Packaging for secretion

34 Identify the function of these endoplasmic reticulum ribosomes lysosomes centrioles cilia/flagella chloroplasts vacuole contractile vacuole Transport system, site for reactions to occur Site of protein synthesis. Some are found free in the cytoplasm Most are found attached to the endoplasmic reticulum Site of photosynthesis Storage of food and water In plants provides strength and structure to cell Storage of wastes Most contain enzymes that break down substances Forms spindle during cell division Movement Pumps out excess water, hence maintaining water balance in the cell


Download ppt "The cell Cell theory: All living things contain cells. All cells come from other cells."

Similar presentations


Ads by Google