Chpt 21-defining life and it's origins

Question 1

define abiotic

Answer 1

physical factors in the environment

Question 2

define biotic

Answer 2

living components of the environment

Question 3

what are the seven characteristics of life?

Answer 3

display order
harness and use energy
reproduce
respond to stimuli
exhibit homeostasis
grow and develop
evolve

Question 4

what is a cell?

Answer 4

the fundamental units of life

Question 5

define emergent property.

Answer 5

new property that forms when simpler objects associate to increase complexity of the resulting combo

Question 6

what is meant by the statement “life displays emergent properties?”

Answer 6

the 7 properties of life emerge from much simpler interactions, for example macromolecules interacting to create cellular processes

Question 7

define abiotic synthesis

Answer 7

mlcls produced in the absence of life, such as the first macromolecules

Question 8

what was the first experiment to determine the abiotic formation of macromolecules, critical to life?

Answer 8

miller’s reaction chamber experiment

Question 9

name three macromolecule origin hypothesis

Answer 9

the reducing atmosphere hypothesis, the deep sea vent hypothesis and the extraterrestrial organs hypothesis

Question 10

define macromolecules and give examples

Answer 10

biologically important mlcls that can be synthesized outside of living cells with an input of E, includes lipids, nucleic acids, proteins and polysaccharides

Question 11

which macromolecules orgin hypothesis completely PROVES that abiotic production of life’s chemicals is possible?

Answer 11

the ET orgins hypothesis

Question 12

define polymer

Answer 12

macromolecules formed from the bonding of individual monomers

Question 13

define monomer

Answer 13

subunits that links together to form polymers during polymerization

Question 14

what is the monomer of nucleic acids?

Answer 14

nucleotides

Question 15

what is the monomer of proteins

Answer 15

amino acids

Question 16

what is the monomer of polysaccharides, such as starch and cellulose

Answer 16

simple sugars

Question 17

polymers are synthesized by…

Answer 17

dehydration

Question 18

define enzyme

Answer 18

a protein based catalyst

Question 19

what is the clay hypothesis?

Answer 19

formation of short nucleic acids and polypeptides can be synthesized on clay surfaces

Question 20

what is the difference between a reducing atmosphere and an oxidizing one?

Answer 20

A reducing atmosphere is an atmospheric condition in where oxidization is prevented by reducing gases, such as O2 and CO2. whereas an oxidizing atmosphere oxidizes immersed surface compounds, for example, the O2 rich atmosphere on earth.

Question 21

define selectively permeable

Answer 21

Membranes that selectively allow, impede, or block the passage of atoms and molecules.

Question 22

what three things do modern life forms need to survive on a microscopic level?

Answer 22

cells, systems to store genetic info and systems to harness energy

Question 23

define protobiant

Answer 23

abiotically produced organic molecules surrounded by a membrane, act as a bilayer of early lipid spheres

Question 24

what were lipid spheres

Answer 24

protobiants that allowed for metabolic runs to occur, similar to present day lipid vesicles

Question 25

how did lipid spheres allow for metabolic runs to occur?

Answer 25

Conc. of mlcls was higher in closed off environment and a greater complexity of molecules was maintained

Question 26

what is a liposome

Answer 26

self assembly of phospholipids that create a bilayer or vesicle to isolate organic molecules

Question 27

define the central dogma

Answer 27

the flow of genetic material within a biological system, generally DNA to RNA to proteins

Question 28

define gene

Answer 28

a unique dna sequence

Question 29

define ribozymes

Answer 29

an rna based catalyst, part of the biochem machinery of all cells,catalyzations lead to their own synthesis

Question 30

Put the following in evolutionary order: protein rna dna

Answer 30

rna protein dna

Question 31

why is dna better than rna for storing info (3 reasons)

Answer 31

dna is more stable, base uracil replaces thymine, dna is double stranded

Question 32

how could alkaline hydrothermal vents have been a free source of E for early organisms?

Answer 32

they were constantly out of equilibrium because of their low conc. of H+ compared to the ocean, so the H+ conc. gradient could synthesize ATP

Question 33

define anerobic

Answer 33

without O2

Question 34

What processes take place in an Energy-coupling reaction

Answer 34

oxidization and reduction

Question 35

what characteristics of life do viruses violate

Answer 35

they lack the ability to reproduce on their own

Question 36

Why would the accumulation of organic material on early Earth be important for the formation of protobionts?

Answer 36

It would allow the chance assembly of molecules into membrane-bound aggregations.

Question 37

As the planet’s atmosphere slowly accumulated O2, starting about 3 billion years ago, what pre-organelle-like structure began to develop in the form of aerobic prokaryotes ingested by other, predatory prokaryotes?

Answer 37

Mitochondria

Question 38

What is believed to have led to the formation of tissues and organs in complex eukaryotes?

Answer 38

cells that are specialized