Chapter 4 -5 Flashcards Preview

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Flashcards in Chapter 4 -5 Deck (20):
1

What does the Endosymbiotic Theory state?

That mitochondria & chloroplasts evolved from ancient bacteria.

2

Why did they come up with the Endosymbiotic Theory?

Because mitochondria & chloroplasts resemble bacteria...
- same in size
- divide on their own
- have own DNA, ribosomes

3

What does the cytoskeleton do?

helps organize cell structure and activites

4

What is the cytoskeleton made up of?

a network of protein fibers

5

What are the 3 types of the cytoskeleton?

Microfilaments, Intermediate Filaments, Microtubules

6

Describe microfilaments.

Slender, composed of actin subunits

7

What is the function of microfilaments?

enable cells to change shape and move
creates Pseudopods (false feet)

8

Describe Intermediate filaments.

In between size and most permanent.
has fibrous proteins/keratin

9

What is the structure of intermediate filaments?

to reinforce the cell/nucleus

10

Describe microtubules.

Hollow tubes of tubulin subunits that originate from centriole area

11

What are the functions of microtubules?

involved in cell shape
vesicle/organelle mvmt
chromosome mvmt
work with kinesin motor proteins
move the entire cell

12

What is the structure of microtubules?

9+2 arrangement

13

What do eukaryotic cell surfaces and junctions do?

protect, support, and join cells
interactions with env. and other cells.

14

What is the plant cell wall?

The structural component around the PM
Has cellulose and pectin scretions

15

How do cells communciate?

junctions called plasmodesmata - channels connect and allow cells to share water food, and chemical messages.

16

What does the Extracellular matrix consist of?

cellular secretions
- a sticky layer of polysaccharides
- protein fibers (Collagen)

17

What is the function of the ECM?

binds cells into tissues
protect and suppport

18

What do tight junctions do?

bind cells together into leakproof sheets

19

What do adhering junctions do?

link animal cells

20

What do gap junctions do?

Allow substances to flow from cell to cell