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A View of the Cell.

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Presentation on theme: "A View of the Cell."— Presentation transcript:

1 A View of the Cell

2 From Molecules to Cells The Evolution of Cells
Life arose in the oceans Molecules collide and reactions take place Larger biomolecules form (nucleic acids, lipids …) Membranes spontaneously form from lipid materials – provides a boundary Cells begin to replicate; transfer genetic material

3 Why do we study cells?

4 The cell theory is made up of three main ideas:
All organisms are composed of one or more cells The cell is the basic functional unit of organisms Schleiden – botanist (1838) - all plants are composed of cells Schwann – zoologist (1839) - all animals are composed of cells All cells come from preexisting cells Virchow – physician (1855) - all cells come from other cells

5 Activities of life Most everything you think of a whole organism needing to do, must be done at the cellular level… reproduction growth & development energy utilization response to the environment homeostasis

6 Relationship between structure & function
Diversity of Cells Relationship between structure & function

7 ALL CELLS… contain cytoplasm (fluid-filled interior)
are surrounded by a plasma membrane contain DNA (genetic material) in the form of chromosomes/chromatin have ribosomes (organelles that make proteins)

8 Two Cell Types Prokaryotic = no true nucleus
1st to evolve Bacterial cells no membrane bound organelles Smaller size Eukaryotic – has a nucleus contain membrane bound organelles much larger classified as either plant or animal cells


Ribosomes DNA Plasma Membrane Cytoplasm

11 EUKARYOTIC CELLS - Plant & Animal Cells
Nucleus (containing DNA) plasma membrane ORGANELLES (membrane bound) Ribosomes

12 What jobs do cells have to do?
transport materials, maintain homeostasis Take in what is needed; get rid of waste make proteins proteins control every cell function make energy for daily life; for growth build more cells growth reproduction repair

13 Maintaining Homeostasis
Homeostasis = regulation maintenance of a stable internal environment Requires bringing in & storage of needed materials Transporting materials to their intended destination Elimination of waste materials

14 What happens if an organelle (like a lysosome) doesn’t work?
don’t digest a biomolecule instead biomolecule collects in lysosomes lysosomes fill up with undigested material lysosomes grow larger & larger eventually disrupt cell & organ function Tay-Sachs disease lipids build up in brain cells child dies before age 5 Tay-Sachs

15 Making Proteins: The Endomembrane system

16 endoplasmic reticulum
nucleus protein on its way! TO: DNA RNA TO: vesicle TO: vesicle ribosome TO: protein finished protein Golgi apparatus Making Proteins

17 Mitochondria & Chloroplasts
Making Energy Mitochondria & Chloroplasts BOTH: transform energy double membranes contain own DNA self-replicate Dividing mitochondria Dividing Bacteria

18 Endosymbiotic theory 1981 | ??
Mitochondria & chloroplasts were once free living bacteria became engulfed by a larger eukaryote evolutionary advantage for both one supplies energy the other supplies raw materials & protection Lynn Margulis U of M, Amherst

19 Endosymbiosis Evolution of eukaryotes PLANT CELLS mitochondria
chloroplast Early EUKARYOTE Engulfing photosynthetic Prokaryote Engulfing Aerobic Prokaryote Early PROKARYOTE mitochondria ANIMAL CELLS

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