Lecture 7: Multicellularity Flashcards Preview

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Flashcards in Lecture 7: Multicellularity Deck (17)
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1
Q

What do cells need in order to communicate

A

they need to be physically related to each other

2
Q

ECM

A

• Animal cells
• Cells secrete glycoproteins into extracellular fluid, weave together to form matric
• Cells express integrins on mb, attach to ECM
• Provides strength and rigidity to tissues
o Cartilage, bone, skin
• Organize cells, allow them to move or stay in place
• Provide signals to cells to guide function or development
• Contains adhering proteins
o Stick components of the ECM together and cells to ECM
• Fibers throughout offer structure for cell support, keep cells together, resiliency
o stitches
• Contains structural proteins
o Give the tissues strength and elasticity

3
Q

Fibronectin

A

protein of ECM

connectes cells to ECM, organizes components

4
Q

laminin

A

protein of ECM

connects cells to ECM, organizes components. Found in top layers of skin, especially

5
Q

collagen

A

protein of ECM

provides tensile strength in deep skin, organs, bones, cartilage, tendons

25% of total protein mass in body
75% of protein in skin

6
Q

elastin

A

forms elastic fibers for stretch and recoil

7
Q

how is collagen made

A
  • Cells produce individual collagen fibers
  • Immediately organize into a triple helix
  • Outside the cell, collagen helices organize into larger collagen fibers
8
Q

loss of collagen

A

caused by rapid growth of any body site (genetic predisposition)

9
Q

importance of elastin

A
  • Stretch and recoil

* Skin, some cartilage, blood vessels

10
Q

loss of elastin

A
  • Sped up by toxins (like nicotine) and UV damage

* Wrinkles

11
Q

proteoglycans

A
  • ECM also contains polysaccharides
  • Repeated disaccharide units attached to a central protein
  • Weave together and bind water, creating a gel that cushions cells and organs
12
Q

tight junctions

A

• Zip the membranes of two cells together so that nothing can slip in between them

13
Q

desmosomes

A

• Kind of linked but things can pass between

14
Q

gap junction

A
  • Form a pore from the inside of cell to the inside another so things can diffuse across the membrane
  • Hold hands but stick ur finger in an electric socket; electricity will pass between the two people
15
Q

adhering junctions

A

connect cells to ECM

• Membranes proteins called integrins connect cytoskeleton to ECM proteins

16
Q

tissues

A

a group of cells having similar function

17
Q

4 tissue types

A

o Epithelial (skin/top layer; forms a boundary)
o Connective: diverse: connect things to one another; cartilage
o Nervous: brain and spinal cord; deliver messages to other parts of your body
o Muscle: contract to form movement