Lec 27

Question 1

Cell crawling is done by

Answer 1

Actin or actin binding proteins

Question 2

Amoeba

Answer 2

Cell crawling + phagocytosis to eat bacteria for food

Question 3

Neutrophils (WBCs)

Answer 3

Cell crawling and phagocytosis

Eat bacteria for defense and food

Question 4

Young neurons

Answer 4

Extend their axons to contact target cells

Question 5

Steps of cell crawling

Answer 5

Detection

Extension (front end)

Retraction (back end (does not happen in young neurons))

Question 6

Detection

Answer 6

Diffusible molecules are used by amoeba and WBCs

Allows them to “smell” the bacteria

Question 7

Young neuron detection

Answer 7

There is a fixed path towards their detection

Question 8

Diffusible molecule

Answer 8

Eukaryotes do not make them

Modified by bacteria

Question 9

Extension

Answer 9

Large projection on amoeba and WBC

Small projection on neuron growth cone for young neuron

Question 10

Mechanism of extension

Answer 10

Protein assembly

G-actin normally attaches to make F-actin

This process is sped up by Profilins

Actins form into 1D, 2D, or 3D formation

Question 11

Retraction

Mechanism

Answer 11

Dismantle the F-actin in the middle of the cell back into G-actin

Contraction occurs at the back of the cell through contraction bundles

Question 12

Contraction bundles

Answer 12

Actin filaments working with myosin

Question 13

Unsuccessful amoebas and WBCs go

Answer 13

Hungry

Question 14

Unsuccessful neurons are

Answer 14

Killed