Life at the Cellular Level

Question 1

What is the cell?

Answer 1

The functional unit of all living things

Question 2

Why are cells so small?

Answer 2

So there is an increased surface area for essential cellular processes such as diffusion

Question 3

What is the main difference between a prokaryote and eukaryote?

Answer 3

Eukaryote has a nucleus

Prokaryote does not have a nucleus

Question 4

Describe a prokaryotic cell

Answer 4

Lack nuclear membrane
No mitochondria
Have no membrane bound structures
Have DNA but it is not bound in a membrane

Question 5

Describe a eukaryotic cell

Answer 5

Have a nucleus with a nucleus membrane

Have membrane bound structures

Question 6

What is a stem cell?

Answer 6

Unspecialised cell that differentiates to become a specialised cell

Question 7

What is a totipotent stem cell?

Answer 7

Has total potential

Can give rise also to both embryonic and placenta cells

Question 8

What is a pluripotent stem cell?

Answer 8

Can develop into all cell types in the body but not placenta or embryonic

Question 9

Multipotent

Answer 9

cells such as those from bone marrow which can differentiate into specific groups of cells
Multipotent do not have total potential

Question 10

Describe differentiation

Answer 10

Different genes are expressed meaning that different proteins are made - its the proteins in a cell that determine that cells function

Question 11

How do cancerous cells divide?

Answer 11

without any control or co-ordination

Question 12

Normally what will happen to a damaged cell?

Answer 12

It will undergo apoptosis

Question 13

What is apoptosis?

Answer 13

Programmed cell death

Question 14

Apoptosis is intimately coupled with what other process?

Answer 14

Cell proliferation

Question 15

What are the 4 different types of tissues in the body ?

Answer 15

Epithelial
Connective
Nerve
Muscle

Question 16

What is the order from cells to organisms?

Answer 16

Cell, tissue, organ, system , organism

Question 17

What component makes up the cell membrane?

Answer 17

Lipids

Question 18

What is the function of the plasma membrane?

Answer 18

To act as as elective barrier for the cell

Question 19

Membrane lipids are amphipathic what does this mean?

Answer 19

Means they have a hydrophilic head and a hydrophobic tail

Question 20

Some proteins in the membrane span the entire cell membrane what are these called?

Answer 20

Integral proteins

Question 21

Other proteins only make contact with the cell membrane what are these known as?

Answer 21

Peripheral proteins

Question 22

Does passive diffusion require energy?

Answer 22

No

Question 23

Does active transport require energy?

Answer 23

Yes

Question 24

Explain active transport

Answer 24

Process that requires energy to move against a concentration gradient, usually in the form of ATP

Question 25

Explain passive diffusion

Answer 25

No energy is required as it moves down a concentration gradient

Question 26

What is endocytosis?

Answer 26

When something is engulfed into the cell - the membrane is invaginated and is stored in a vesicle

Question 27

What is exocytosis?

Answer 27

When something is released from the cell, for example a neurotransmitter being released in a vesicle

Question 28

What are gap junctions in cell adhesion?

Answer 28

small passages that allow the movement of small water soluble molecules from cell to cell

Question 29

Where are endocrine signals carried?

Answer 29

In the blood

Question 30

What is the RER studded with?

Answer 30

Ribosomes

Question 31

Which cells do not contain mitochondria?

Answer 31

RBC

Question 32

What do mitochondria have their own of?

Answer 32

DNA

Question 33

Why do mitochondria have their own DNA?

Answer 33

Because they synthesis most of their own proteins

Question 34

Why is the double membrane in mitochondria so important?

Answer 34

Because it allows for the H+ gradient to be formed at the ETC

Question 35

Where is most of the energy from respiration generated?

Answer 35

In the mitochondria

Question 36

What does the nucleus contain?

Answer 36

DNA, nucleoprotein and some RNA

Question 37

What are heterochromatin?

Answer 37

Denser areas where DNA is still coiled - not expressing

Question 38

What it euchromatin?

Answer 38

Lighter areas where DNA is unwrapped and active- is expressing

Question 39

What does the golgi apparatus do?

Answer 39

Takes in proteins from the ER to be modified in some way

Question 40

What do lysosomes separate?

Answer 40

Enzymes from the rest of the cell

Question 41

Why are lysosomes so important?

Answer 41

Because they store digestive enzymes in vesicles so they don’t harm the rest of the cell

Question 42

What are cilia and flagella made of?

Answer 42

Microtubules

Question 43

Which is longer cilia or flagella?

Answer 43

Flagella

Question 44

Give an example of where cilia are found

Answer 44

Lining the respiratory tract

Question 45

What bond are amino acids linked by?

Answer 45

Peptide bonds

Question 46

Is rNA single or double stranded?

Answer 46

Single stranded

Question 47

What base replaces thymine in rNA?

Answer 47

Uracil

Question 48

What can free energy be used to define?

Answer 48

The spontaneity of a reaction

Question 49

A spontaneous reaction must decrease what and increase what?

Answer 49

Decrease enthalpy

Increase Entropy

Question 50

What is the problem with G=0?

Answer 50

It is incompatible with life

Question 51

What does free energy flow between?

Answer 51

Catabolic and anabolic processes

Question 52

What is each step in a metabolic pathway catalysed by?

Answer 52

An enzyme