Biology Test Ch. 2 Flashcards Preview

Biology > Biology Test Ch. 2 > Flashcards

Flashcards in Biology Test Ch. 2 Deck (51)
Loading flashcards...
1
Q

Chemistry - the study of…

A

structure and behaviors of atoms and molecules

2
Q

4 main classes of biological molecules

A
  • carbohydrates
  • lipids
  • proteins
  • nucleic acids
3
Q

Elements

A

pure substances in periodic table

4
Q

H
Atomic #?
Atomic mass?

A

Hydrogen

  • atomic # = 1
  • atomic mass = 1
5
Q

Ag

A

Silver

6
Q

O
Atomic #?
Atomic mass?

A

Oxygen

  • atomic # = 8
  • atomic mass = 16

-HAS COVALENT BONDS

7
Q

Compounds

A

combinations of elements

8
Q

CO2

A

carbon dioxide

9
Q

HCl

A

hydrochloric acid

10
Q

living organisms are made up of what elements? (6)

A
(C) arbon
(H) ydrogen
(O) xygen
(P) hosphorus
(S) elenium
(N) itrogen
11
Q

ATOMS =

A
  • protons
  • neutrons
  • electrons
12
Q

Nucleus

A
  • set # of protons

- # neutrons may very

13
Q

Atomic number

A

-# of protons (in nucleus)

-

14
Q

Atomic mass (AMU) =

A

protons + # neutrons

15
Q

First energy shell can hold…

A

2 e-

16
Q

Second energy shell can hold…

A

8 e-

***LIKE TO HAVE 8 ELECTRONS IN OUTTER SHELL

17
Q

Inner shells are filled before

A

outer shells

18
Q

Isotopes

A

same form of element, w/ different #’s of neutrons

19
Q

Radioactive isotopes

A

unstable, may emit energy when changes to a stable form

20
Q

Ions

A

ATOMS with + or - charges

ex. H+, Cl-
21
Q

Molecules

A

2 or more atoms bonded together

22
Q

Covalent Bonds

A
  • atoms share pairs of e-

- FOUND IN MOLECULES

23
Q

Non-polar Bonds

A

e- shared EQUALLY

ex. O2, CH4

24
Q

Polar Bonds

A

e- shared UNEQUALLY

 ex. H2O
25
Q

Ionic Bonds

A
  • bonds btwn oppositely charged ions

ex. salt

26
Q

Hydrogen Bonds

A

-when a partially (+) HYDROGEN is attracted to partially (-) ATOM

27
Q

Hydrogen Bonding makes…

A

life possible

28
Q

Hbonds affect physical…

A
  • properties of water
  • why water is slow to heat
  • unusual amount of heat is required to evaporate water
    ex. sweating
29
Q

**Behavior of water is affected by…

A

cohesion and adhesion

30
Q

Cohesion

A

like molecules cling together

31
Q

Adhesion

A

UNLIKE molecules cling together

32
Q

Ice is LESS dense than…

A
  • water
  • floats on water
    ex. frozen layer of a lake
33
Q

Water is a

A

solvent

34
Q

Solvent

A

does the dissolving

35
Q

Solute

A
  • dissolves in solvent

ex. polar molecules, ions

36
Q

HydroPHILIC

A
  • dissolves in water

ex. salt, sugar

37
Q

HydroPHOBIC

A

does NOT dissolve in water

ex. oil, fats

38
Q

Acids

A

release H+ when dissolved in water

39
Q

Base

A

accepts H+ when dissolved in water

40
Q

Acidi pH #’s

A

0 - 7

41
Q

Basic pH #’s

A

7 - 15

42
Q

Neutral pH #

A

7

43
Q

Buffers

A
  • moderate changes in pH
  • absorb or release H+
    ex. bicarbonate/carbonic acid buffering system in blood
44
Q

Neutrons =

A

atomic mass - atomic #

45
Q

neutrons =

A

atomic mass - atomic #

46
Q

Hbonds are ______ than covalent bonds

A

WEAKER

47
Q

Mass is always the BIGGER…

A

in periodic table

48
Q

Hydrogen Bonds are usually…

A

-btwn 2 different molecules

49
Q

______ bonds allow bugs to walk on water

A

hydrogen

50
Q

Water is an example of ______ bond

A

Polar

51
Q

Salt has _____bonds

A

Ionic