Ch. 2 The Chemical Context of Life

Question 1

how is emergent properties found in this ch?

Answer 1

It applies to the lowest level of biological organization-to the ordering of atoms into molecules and to the interactions of those molecules within cells.

Question 2

Why can we use the terms “weight” and “mass” interchangeably on Earth?

Answer 2

The weight of an object is a measure of its mass (i.e. the heavier something is, the more mass it has, when we are in one location with constant gravity)

Question 3

What are the four basic ingredients Greek philosophers proposed as the basis for all the variety of matter?

Answer 3

air, water, fire, earth

Question 4

how many elements occur naturally, as we know now?

Answer 4

92

Question 5

how many elements does life require?

Answer 5

25 of the 92 natural elements

Question 6

what elements make up the majority of living matter, and how much?

Answer 6

CHNOPS=96%. A few other elements account for most of the remaining 4% of organism’s weight.

Question 7

list the hierarchy of biological order

Answer 7

atom, molecule, organelle, cellular, tissue, organ, organ system, organism (a.m.o.c.t.o.o.o)

Question 8

what are trace elements?

Answer 8

those required by an organism in only minute quantities

-some (ex. Fe) are needed by all, others are only needed by some species

Question 9

What do the properties of chem elements and of the compounds they form, including the compounds crucial to life, result from ultimately?

Answer 9

the STRUCTURE of atoms

Question 10

what is the unit of measurement for atoms and subatomic particles?

Answer 10

daltons (in honor of john Dalton, the br scientist who helped develop atomic theory around 1800) (same as amu-atomic mass unit)

Question 11

mass of proton (which is roughly same as mass of neutron)?

Answer 11

close to 1 dalton (1.7 *10^-24 grams)

Question 12

electron’s mass?

Answer 12

1/2000 that of neutron/proton-electron’s mass is ignored when computing total mass of atom

Question 13

atomic number?

Answer 13

of protons, written as a subscript to left of symbol for element

Question 14

mass #

Answer 14

written as superscript to left of an element’s symbol

Question 15

most common carbon isotope?

Answer 15

c-12=99% of all carbon in nature

Question 16

radioactive isotope?

Answer 16

nucleus decays spontaneously, giving off particles and energy.
used as tracers that follow atoms through metabolism, the chemical processes of an organism

Question 17

what is energy?

Answer 17

ability to do work

Question 18

potential energy?

Answer 18

• energy that matter stores bec/ of its position or location

- matter has tendncy to move to lowest possible state of potential energy

Question 19

how does potential energy (P.E) relate to an e-‘s distance from the nucleus?

Answer 19

the more distant e-‘s are from positively charged nucleus, the more p energy they have

Question 20

Electron Configuration and Chemical Properties?

Answer 20

first shell-no more than 2 e’s (s-spherical, 2 orbitals)
p-8 (dumbell, 3 orbitals)
each 2p orbital is positioned at right angles to the other 2
d-10
f-14
valence e’s or valence shell provides for chem behavior
inert=chemically unreactive

Question 21

orbital

Answer 21

• 3D space that e’ is found 90% of the time

- e’s in different orbitals have nearly the same energy, but move in various volumes of space