Lecture 1-Introduction to Cells and Key Biochemical Concepts

Question 1

what does the cell theory state

Answer 1

1. Cells are the fundamental units of life
2. All organisms are composed of cells
3. All cells come from pre-existing cells

Question 2

unicellular organisms

Answer 2

a single cell carries out all the functions of life

Question 3

multicellular organisms

Answer 3

made of many cells that are specialized for different functions – tissues and organs

Question 4

central dogma

Answer 4

DNA makes RNA makes proteins

Question 5

why aren’t viruses live

Answer 5

they can’t replicate on their own

Question 6

Historical landmarks in determining cell structure

Answer 6

1. Hooke: used primitive microscope to describe small chambers in sections of cork called cells
2. Leewenhoek: discovered protozoa
   3.Brown: observed orchids and clearly described their nucleus
   4.Scheilden and Schwann: propose the cell theory (nucleated cell is universal building block of plant and animal tissues)
   5.Virchow: every cell stems from another cell
3. Strausburger: draws a living plant cell dividing over 2.5 hours

Question 7

features of prokaryotes

Answer 7

-No nucleus: their DNA floats freely in the cell
-No (or rudimentary) internal membranes
-Very basic cytoskeleton

Question 8

features of eukaryotes

Answer 8

-Have a nucleus containing DNA
-Complex internal membrane system
-Extensive cytoskeleton

Question 9

domains of prokaryotes

Answer 9

Bacteria and Archaea

Question 10

habitats of archaea

Answer 10

hostile environments such as acidic hot springs, volcanic vents, marine sediment, cows’ stomachs,

Question 11

features of a nucleus

Answer 11

-information store
-surrounded by a double membrane (nuclear envelope)
-contains nucleolus (rRNA and ribosome synthesis)

Question 12

what are organelles surrounded by

Answer 12

one or more membranes made up of lipid bilayers that form a physical barrier from the cytosol

Question 13

features of internal membranes

Answer 13

-Allows different protein contents and chemical environments to be maintained
-Allows each organelle to have a specialised function

Question 14

features of the mitochondria

Answer 14

-energy generation/ generate ATP
-site of oxidative phosphorylation
-extensively folded inner membrane for increased surface area for cellular respiration (cristae)
-forms complex dynamic networks in the cell
-apoptosis

Question 15

origin of mitochondria and membrane organelles

Answer 15

the enclosure of bacterial ectosymbiont by archaeal membrane fusion led to escape of endosymbiont into cytosol and formation of intracellular compartments

Question 16

features of the endoplasmic reticulum

Answer 16

-synthesis
-makes secretory membrane proteins and also lipids
-dynamic

Question 17

smooth ER

Answer 17

abundant in human cells active in lipid metabolism and in liver for detoxification of lipid soluble compounds

Question 18

sarcoplasmic reticulum

Answer 18

ER derived calcium store in muscle cells: important role during muscle contraction

Question 19

features of the Golgi apparatus

Answer 19

-processing and packaging
-receives lipids and proteins as cargo from ER which transmits to the plasma membrane
-modifies cargo e.g glycosylation
-sorting of cargo to the correct location

Question 20

features of the cytosol

Answer 20

-site of fundamental cellular processes: -*protein synthesis and degradation
*Intermediary metabolism (e.g. glycolysis)
*Location of the cytoskeleton

Question 21

difference between cytoplasm and cytosol

Answer 21

cytoplasm- everything inside the plasma membrane but outside the nucleus including organelles

cytosol- soluble aqueous fraction

Question 22

features of the cytoskeleton

Answer 22

-strength and dynamics
-actin filaments
-microtubules
-intermediate filaments

Question 23

what are the main model prokaryotes, lower eukaryotes and higher eukaryotes

Answer 23

P- E.coli
LE- S cerevisiae (budding yeast), S pombe (fission yeast)
HE- vertebrate cells in culture

Question 24

model organisms: zebra fish

Answer 24

vertebrae developmet

Question 25

model organisms: drosophila melanogaster

Answer 25

classical genetics, development

Question 26

model organisms: arabidopsis thaliana

Answer 26

plant molecular biology and development

Question 27

model organisms: caenorhabditis elegans

Answer 27

genome sequencing, programmed cell death

Question 28

what is needed to make ATP

Answer 28

ADP + phosphate + energy

Question 29

what does fast hydrolysis of ATP drive

Answer 29

motor proteins, which are specialized proteins that produce movement in cells e.g kinesin

Question 30

how are amino acids grouped

Answer 30

acidic basic uncharged polar non polar

Question 31

what amino acids undergo phosphorylation

Answer 31

serine threonine tyrosinew

Question 32

which amino acids undergo O-glycosylation

Answer 32

serine threonine

Question 33

which amino acids undergo N-glycosylation

Answer 33

asparagine

Question 34

which amino acid can form a disulphide bond and why

Answer 34

two cysteine side chains as they contain sulphur

Question 35

consequences of ATP/GTP binding to nucleotides

Answer 35

binding can control protein shape, activity and function

Question 36

how can phosphorylation control protein function

Answer 36

addition of a phosphate group from ATP to serine, threonine or tyrosine controls protein function

Question 37

what does phosphorylation do (6)

Answer 37

cell growth gene expression cell survival cell cycle cell division metabolism