The mitochondria and the Extracellular Matrix

Question 1

what is the mitochondria?

Answer 1

powerhouse of the cell.

the Krebs cycle takes place in the mito

Question 2

what is the endosymbiont theory?

Answer 2

mitochondria may have evolved from a symbiotic relationship between ancient prokaryotes and eukaryotes. like prokaryotes, mitochondria have their own DNA (circular) and replicates independently from the cell. they also have their own ribosomes!
however most proteins used by the mitochondria are coded for by the nucleus DNA and not mito DNA

Question 3

Universal genetic code

Answer 3

some of the codons in the mitochondria differ from the codons in the rest of the cell , presenting an he exception to the universal genetic code.

Question 4

how is mitochondria DNA passed?

Answer 4

maternally.

Question 5

how many layers is the mitochondria covered by?

Answer 5

2 phospholipid bilayers. the inner membrane invaginate to form cistae. its the inner membrane that hols the ETC. between the inner and the outer mem is the intermembrane space.

Question 6

what are the roles of the extracellular matrix?

Answer 6

provide structural support and help to determine the cell shape and motility and affect cell growth
- ECM is basically stuff that surrounds the cell and its formed by the cell itself.

Question 7

what are the 3 classes of molecules that make up animal cell matrices?

Answer 7

glycosaminoglycans and proteoglycans
structural proteins
adhesive proteins

Question 8

what are glycosaminoglycans?

Answer 8

polysaccharides that typically have proteoglycans attached. they make up over 90% of the matrix by mass.

Question 9

what are structural proteins?

Answer 9

they provide the matrix with strength. the most common one in the body is collagen. it gives cartilage and bone their tensile strength.

Question 10

what do the adhesive proteins do?

Answer 10

adhesive proteins help individual cells within a tissue stick together

Question 11

what is the basal lamina?

Answer 11

thin sheet of matrix material that separates epithelial cells from support tissue . it acts as a sieve type barrier, selectively allowing the passage of some molecules but not others.

Question 12

what is the glycocalyx?

Answer 12

it separates the cell membrane from the extracellular matrix

Question 13

what are groups of cells called?

Answer 13

tissue!

Question 14

what are the four basic types of tissue in animals?

Answer 14

epithelial tissue, muscle tissue, connective tissue and nervous tissue.

Question 15

What is the importance of intercellular communication?

Answer 15

cells must be able to communicate with each other so that the organism can function as a single unit

Question 16

communication between the cells is accomplished chemically via which three types of molecules?

Answer 16

neurotransmitters
local mediators
hormones
these methods are governed by the nervous system, the paracrine system and the endocrine respectively!

Question 17

Distinctions between the methods of communication are

Answer 17

neurotransmitters travel over short intercellular gaps
local mediators function in the immediate area around the cell from which they are released
hormones travel throughout the organism via the blood stream

Question 18

neuronal transmission is…

Answer 18

rapid, direct and specific

Question 19

hormonal transmission is…

Answer 19

slower, spread throughout the body and affects many cells and tissues in different ways

Question 20

local mediators are released by a variety of cells into the …

Answer 20

interstitial fluid .. which is fluid between the cells.

- the local mediators will when act on neighbouring cells a few mm away

Question 21

what are prostaglandins?

Answer 21

they are local mediators too .. they are fatty acid derivatives
- they affect smooth muscle contraction, platelet aggregation inflammation and other reactions.
Aspirin is a prostaglandin inhibitor and therefore its an anti-inflammatory

Question 22

what are growth factors and lymphokines?

Answer 22

they are also local mediators