{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

CellBio51 - Cell junctions = specialized structures that...

Info iconThis preview shows pages 1–28. Sign up to view the full content.

View Full Document Right Arrow Icon
Cell junctions = specialized structures that hold cells together: Tight junctions Desmosomes Gap junctions
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Animal Cell Junctions Two main functions: 1) helps cells to adhere to each other 2) facilitates communication between cells and facilitates or blocks transport of molecules between cells
Background image of page 2
Tight junctions 1) Link cells together very tightly 2) Do not allow passage of materials in the space between the two cells 3) Do not allow movement of membrane proteins outside the membranes themselves
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Tight Junctions
Background image of page 4
Tight Junctions in red
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Figure 5.7 Junctions Link Animal Cells Together (A) Tight junctions form a quilted seal, preventing movement of molecules in the space between the cells.
Background image of page 6
Desmosomes 1) allows space between the cells 2) does not limit movement in the space between the two cells
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Figure 5.7 Junctions Link Animal Cells Together (B) Desmosomes are like “spot welds”
Background image of page 8
Desmosomes Fig. 5.6 tight junctions A desmosome
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
A Desmosome Visualized by Electron Microscopy Fig. 5.6 / 6.7
Background image of page 10
Gap junctions permits passage of large molecules between two cells made of special connecting protein channels that can open and close called connexons
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Figure 5.7 Junctions Link Animal Cells Together (C) Gap junctions allow communication
Background image of page 12
Section 3 Chromatin, Chromosomes, Cell Cycle in Prokaryotes and Eukaryotes
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Cell Division in Prokaryotes and Eukaryotes Prokaryotic Chromosomes and Eukaryotic Chromosomes
Background image of page 14
4 signals required before cell division 1. Reproductive signal 2. Replication of DNA ++ 3. Segregation 4. Cytokinesis
Background image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
The Chromosome in Prokaryote Cells There is one chromosome (the DNA is contained in a single chromosome !)
Background image of page 16
The Chromosome in Prokaryote Cells There is 1 chromosome The stretched out length of the chromosome is ~ 1500 μm, but a bacterium is only 1 μm in diameter Its DNA must be compacted!!!
Background image of page 17

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
The Chromosome in Prokaryote Cells There is 1 chromosome The stretched out length of the DNA is ~ 1500 μm, but a bacterium is only 1 μm in diameter The DNA forms a closed circle and has many loops so it can fit inside the cell
Background image of page 18
The Prokaryotic Chromosome is a Circle A spread out E. coli chromosome as seen by electron microscopy
Background image of page 19

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Cell Division in Prokaryotes The duplicated chromosome is attached to the cell membrane to ensure proper distribution to the daughter cells When the DNA replicates, the attachment points separate as the cell divides The cells divide by fission (splitting into 2 cells)
Background image of page 20
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}