Life at a cellular level.

Question 1

What is a prokaryotic cell?

Answer 1

Bacteria. No membrane bound structures. No nucleus / mitochondria. DNA chills.

Question 2

What is a eukaryotic cell?

Answer 2

Found in humans and plants. Has membrane bound structures, and a nucleus.

Question 3

what is a multipoint stem cell?

Answer 3

A stem cell that can differentiate into one cell type. They can only carry out one or two roles.

Question 4

What type of cell can differentiate into all cells in the body?

Answer 4

A pluripotent embryonic stem cell.

Question 5

How is differentiation caused in stem cells?

Answer 5

changes in Gene expression. e.g cell fusion.

Question 6

What is the term for programmed cell death?

Answer 6

Apoptosis

Question 7

what does apoptosis, programmed cell death do?

Answer 7

It controls multicellular development.

Question 8

What is the term for the rapid reproduction of cells?

Answer 8

Proliferation.

Question 9

What is the plasmalemma ?

Answer 9

Just another word for the cell membrane.

Question 10

what does amphipathetic mean? (in terms of cell membranes)

Answer 10

Hydrophobic head, hydrophilic tail.

Question 11

Name 6 functions of the cell membrane?

Answer 11

1) transport
2) enzymatic activity
3) signal transduction receptors
4) intercellular joining
5) cell to cell recognition.
6) attachment to cytoskeleton and extracellular matrix.

Question 12

what is endocytosis?

Answer 12

The uptake of big things. by invaginating and forming a vesicle.

Question 13

what is exocytosis?

Answer 13

Proteins that are packaged in golgi network. Vesicle breaks off and travels to cell membrane. e.g regulates secretion.

Question 14

what is a tight junction.

Answer 14

Two cells sealed together, with no gap. It creates a physical barrier, is dependant on calcium.

Question 15

Where are tight junctions found?

Answer 15

In the intestines, kidneys, blood brain barrier.

Question 16

What is an adherens junction?

Answer 16

Links actin filaments in two different cells.

Question 17

what is a desmosomes?

Answer 17

links keratin filaments in two different cells.

Question 18

What is a Gap junction?

Answer 18

it links two cells but forms a channel which is constantly open. It allows cell to cell communication.

Question 19

Where are gap junctions found?

Answer 19

Heart muscle, liver, pancreas.

Question 20

What is connexions?

Answer 20

6 subunit membrane proteins.

Question 21

How does disease effect cell adhesion?

Answer 21

Tight junctions can be damaged, e.g. a tumour can break off its original tumour and spread to other parts of cell to recolonize.

Question 22

What is contact dependant cell signalling?

Answer 22

Requires membrane bound signalling molecules.

Question 23

Describe paracrine cell signalling.

Answer 23

Receptors from cells target can target more than one localised cells. They use a local mediator.

Question 24

What type of cell signalling involves a neurone and a synapse.

Answer 24

Synaptic cell signalling.

Question 25

What type of cell signalling can provoke responses around the whole body by releasing signalling molecules into the blood stream?

Answer 25

Endocrine.

Question 26

What is the inner membrane of the mitochondria called?

Answer 26

The cristae.

Question 27

What happens in the mitochondrial matrix?

Answer 27

Calcium binding sides and oxidation of foods.

Question 28

What is the purpose of the cell cytoskeleton .

Answer 28

It maintains shape and support. It also moves organelles.

Question 29

what are the four main elements in the body?

Answer 29

H O N C

Question 30

How are the ten structural elements required by the body gained by the body?

Answer 30

Must intake them through diet.

Question 31

What happens if proteins do not have the ten structural elements?

Answer 31

They may have the wrong shape and function.

Question 32

What type of both is the basis of most molecules?

Answer 32

The Carbon bond. - they can form single bonds, double and triple.

Question 33

What is a chiral carbon?

Answer 33

A carbon with four different groups coming off it.

Question 34

What is the left mirror image and the right mirror image of a chiral carbon called?

Answer 34

Laevo (left) and dextro (right)

Question 35

What are the two laws that govern energy changes?

Answer 35

1) Energy cannot be created or destroyed, just converted from one form to another.
2) All energy changes lead to more disorder in the universe. (increase in entropy)

Question 36

Do cells like order or disorder?

Answer 36

ORDER!

Question 37

How do cells maintain order and how does it affect the surrounding environment?

Answer 37

Cells perform chemical reactions to get more ordered, but release heat into the surrounding environment which causes it to be more disordered.

Question 38

Does DeltaG need to be positive or negative for a spontaneous reaction?

Answer 38

Negative. (The reaction releases energy)

Question 39

What does a spontaneous reaction need.

Answer 39

Decrease in enthalpy or increase in entropy.

Question 40

Do biological processes have positive or negative delta G?

Answer 40

Positive, as they want more order.

Question 41

What is reaction coupling?

Answer 41

it is used to carry out thermodynamically unfavourable reactions. It involves catabolic reactions breaking stuff down and requiring -deltaG, paired with anabolic reactions building stuff up requiring +deltaG.

Question 42

Why can’t biology reaction pathways reach equilibrium?

Answer 42

because the products of one are used in another reaction.