This PowerPoint presentation was used in a Biology class for Emerging Ethnic Engineer Summer Bridge participants. Throughout the course, the

Transcription

1 This PowerPoint presentation was used in a Biology class for Emerging Ethnic Engineer Summer Bridge participants. Throughout the course, the contributions from scientists of underrepresented ethnic groups were highlighted, as is evident in the first two slides. This particular class was on cellular organization. Students had been assigned an organelle to present in the class. Their slides are at the end of this presentation and they taught the concept covered in their slides. Questions were directed to each student to test their understanding during their presentation and to facilitate the learning of all students in the class. PowerPoint presentations were a minor part of the class; most of the course work involved lab and group work. In this section, students learned to use microscopes and conducted an experiment on the growth of archaea, bacteria and yeast in different media.

2 Ernest Everett Just ( ) Pioneering contributions to the cytology and embryology of marine organisms 1916 magna cum laude graduate with PhD, from Univ. of Chicago in experimental embryology Biochemist Explained effect on cell surface of fertilization Experimental parthenogenesis Investigated effect of environment dilute or concentrated sea water, UV radiation, temperature, hydration or dehydration on embryo development demonstrated carcinogenic effects of UV radiation on cells Invited to collaborate in Germany

3 The Biology of the Cell Surface by Just Life is the harmonious communion of events Cells and organisms are more than the sum of their parts Properties of a molecule, cell, tissue or whole organism depends on the properties of the components (the level below) Properties also depend on the level above (the whole into which it is integrated) Similar to modern integrative systems biology

4 Patricia Bath At 16, she derived a mathematical equation for predicting cancer cell growth during a summer program Earned MD in 1968 from Howard University First African American resident at New York University First African-American female to receive a patent for her medical invention, the Laserphaco Probe (1981) Patented two devices for cataract surgery 1976 co-founded the American Institute for the Prevention of Blindness (AIPB)

5 Photomicrograph SEM, Bacillus megaterium Yeast, Saccharomyces cerevisiae

6 Sulfolobus Yellowstone hot sulfur springs

7 Cheek Cells, Human Elodea

8 Size Prokaryotes typically range from 0.1 to 5 um in diameter Eukaryotes are typically um in diameter

9

10

11 Describe factors that limit cell size

12 As a cell gets larger, volume increases faster than surface area. If the radius (r) increases by 10 times, surface area increases by 100 times (r squared), volume increases by 1,000 times (r cubed). A cell's surface area must be large enough to meet the needs of its volume. Most cells are small to maintain a high surface area to volume ratio.

13 Surface area/volume also affects organism or tissue sizes and adaptations to the environment Larger surface area in root system

14 Nucleolus Nucleolus By: Jalynn In a Eukaryotic cell Located in the Nucleus Nucleus contains genetic material, synthesizes proteins (RNA) Nucleolus is the dark-staining material exhibited by nuclei Nucleolus is where the synthesis occurs

15 Contains embedded enzymes that synthesizes carbohydrates, lipids, and steroid hormones Membrane lipids Stores Ca2+ Detoxifies foreign substances Penicilin Stacia

16 The surface is covered in ribosomes (hence the name rough ER) It is the site in which protein synthesis takes place Newly synthesized proteins can be modified to form glycoproteins Manufactures membranes

17 Golgi Apparatus Flattened stacks of membranes that are interconnected. Function: the collection, packing and distribution of molecules synthesized at one location and used at another within the cell or even outside. Molecules come from the ER and enter the cis face of the Golgi Apparatus and exit through the trans face. Tiffany

18 TIGHT JUNCTIONS Wall of cells Only a single cell thick No space between neighboring cells Proteins in membrane of junction move nutrients Kelechi

19 Anchoring Junctions (Desmosomes) Attaches to cytoskeleton of cells or their extracellular matrix Hemidesmosomes link to epithelial cells Cadherins create the link and connect to actin/intermediate filaments Adherens junctions connect to actin filaments ; also a member of integrins Josephine

20 Intercellular bridge Exist in multicellular organisms Connects cells and/or the cell and the extracellular matrix Abundant in epithelial tissue Types gap junction Tight junction Anchoring junctions Communicating junctions

21

22

23