Topic 4-1

Question 1

How long ago was the earth formed?

Answer 1

4.6 billion years ago

Question 2

What were the conditions of the primordial earth?

Answer 2

• frequent and intense lightning
• volcanic activity
• primitive atmosphere
• NO o3 layer
• intense uv rays
• reducing atmosphere

Question 3

what evidence was found in greenland? what did it suggest? and how old is it?

Answer 3

carbon isotopes
3.8 bya
suggest that this is when organic molecules were generated.

Question 4

define stromatolite

Answer 4

• dome shaped rock formed when microorganisms bind particles of sediment together, forming thin sheets

Question 5

what were the earliest fossils

Answer 5

stromatolites

Question 6

how far back to stromatolites date back?

Answer 6

3.4 bya

Question 7

what is the definition of life?

Answer 7

• ## No definition - its too hard to make a universal definition

Question 8

what is NASA’s definition of life?

Answer 8

a self sustaining system capable of Darwinian evolution

Question 9

What is wrong with NASA’s definition of life?

Answer 9

there are things that can’t evolve but are living…. mules

Question 10

Why might a virus be considered alive or not?

Answer 10

• alive - b/c contain nucleic acid and replicate and evolve rapidly
• not alive - b/c they don’t make their own proteins and cannot complete life cycle without invading other living cells

Question 11

What are the & key characteristics shared by cellular life forms?

Answer 11

• Order
• Harness and utilize energy
• Reproduce
• respond to stimuli
• exhibit homeostasis
• grow and develop
• evolve

Question 12

What defines a cell?

Answer 12

• metabolism
• reproduction
• composition- complex organic molecules

Question 13

What is metabolism?

Answer 13

Process through which organisms produce and consume energy to sustain themselves

Question 14

define reproduction

Answer 14

all cells arise from previous cells

Question 15

what are the complex molecules that make up cells?

Answer 15

protein
carbs
lipids
nucleic acids

Question 16

in order for living cells to emerge what needs to happen?

Answer 16

• a means of reproduction
• formation and aggregation of organic molecules

Question 17

how many steps are there to producing simple cells?

Answer 17

4

Question 18

what are the 4 steps/stages to producing simple cells?

Answer 18

1 - abiotic synthesis of small organic molecules
2- Joining these small molecules into macromolecules
3 - package molecules into protocells
4- origin of self replicating molecules

Question 19

explain step 1 - abiotic synthesis of small organic molecules

Answer 19

the reducing atmosphere present in the primordial earth created a potential for the abiotic synthesis of aa sugar lipids nucleotides
miller-urey supported this

Question 20

whos hypothesis was abiotic synthesis of small organic molecules

Answer 20

• oparin/haldane

Question 21

the Miller- urey experiments did what?

Answer 21

supported the oparin/haldane hypothesis -
- their experiments showed that the abiotic synthesis of organic molecules in a reducing atmosphere is possible

Question 22

according to the abiotic synthesis of small organic molecules (miller-urey experiment) organic molecules can be synthesized spontaneously under the conditions _______________

Answer 22

simulating the primordial earth

Question 23

what is step 2 to the origin of life?

Answer 23

Formation of polymers

Question 24

explain - the formation of polymers step

Answer 24

on earth - RNA monomers produced spont from simple molecules
- experiment with hot sand, clay, rock
in space - interstellar star - 4.5 by old chondrite containing 80+ amino acids

Question 25

What experiment was conducted to show the formation of polymers?

Answer 25

Polymers of organic molecules produced by combining aa/nucleotides on hot sand, rock, clay

Question 26

What evidence from space confirmed the formation of polymers?

Answer 26

4.5 billion year old chondrite was found in s austrailia with 80+ amino acids

Question 27

what is a chondrite?

Answer 27

a meteorite containing chondrules - small silicate particles

Question 28

What were the first cells?

Answer 28

protocells

Question 29

what are protocells?

Answer 29

• a group of abiotically produced organic molecules that are surrounded by a membrane or membrane like structure

Question 30

protocells are - 3 things

Answer 30

primitive cell-like structures
some properties of life
may have been precursors of cells

Question 31

what is step 3 to the origin of life?

Answer 31

• packaging of molecules into protocells

Question 32

explain- packaging of molecules into protocells(step 3)

Answer 32

• produce vesicles
• simple reproduction
• liposomes can form
• vesicles form faster in presence of volcanic clay
• vesicles exhibit simple reproduction and metabolism and maintain an internal chemical environment

Question 33

how/when are liposomes formed?

Answer 33

when lipids and other organic molecules are added to water

Question 34

what is a liposome?

Answer 34

type of vesicle made of lipid

Question 35

what is the 4th step to the origin of life?

Answer 35

evolution of mechanisms of heredity

Question 36

in modern cells how is protein made (simple)

Answer 36

DNA - RNA - Protein

Question 37

the first genes were probably …

Answer 37

RNA molecules

Question 38

Ribosomes ….

Answer 38

catalyze many reactions like self splicing and sequences of RNA

Question 39

early genetic material in the “RNA world” probably formed by…

Answer 39

RNA - DNA - Protein