Biology Test Ch. 2 Flashcards Preview

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Flashcards in Biology Test Ch. 2 Deck (51):
1

Chemistry - the study of...

structure and behaviors of atoms and molecules

2

4 main classes of biological molecules

-carbohydrates
-lipids
-proteins
-nucleic acids

3

Elements

pure substances in periodic table

4

H
Atomic #?
Atomic mass?

Hydrogen
-atomic # = 1
-atomic mass = 1

5

Ag

Silver

6

O
Atomic #?
Atomic mass?

Oxygen
-atomic # = 8
-atomic mass = 16

-HAS COVALENT BONDS

7

Compounds

combinations of elements

8

CO2

carbon dioxide

9

HCl

hydrochloric acid

10

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

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

11

ATOMS =

-protons
-neutrons
-electrons

12

Nucleus

-set # of protons
-# neutrons may very

13

Atomic number

-# of protons (in nucleus)

-

14

Atomic mass (AMU) =

# protons + # neutrons

15

First energy shell can hold...

2 e-

16

Second energy shell can hold...

8 e-
***LIKE TO HAVE 8 ELECTRONS IN OUTTER SHELL

17

Inner shells are filled before

outer shells

18

Isotopes

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

19

Radioactive isotopes

unstable, may emit energy when changes to a stable form

20

Ions

ATOMS with + or - charges

ex. H+, Cl-

21

Molecules

2 or more atoms bonded together

22

Covalent Bonds

-atoms share pairs of e-

-FOUND IN MOLECULES

23

Non-polar Bonds

e- shared EQUALLY

ex. O2, CH4

24

Polar Bonds

e- shared UNEQUALLY

ex. H2O

25

Ionic Bonds

-bonds btwn oppositely charged ions

ex. salt

26

Hydrogen Bonds

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

27

Hydrogen Bonding makes...

life possible

28

Hbonds affect physical...

-properties of water

-why water is slow to heat

-unusual amount of heat is required to evaporate water

ex. sweating

29

**Behavior of water is affected by...

cohesion and adhesion

30

Cohesion

like molecules cling together

31

Adhesion

UNLIKE molecules cling together

32

Ice is LESS dense than...

-water

-floats on water

ex. frozen layer of a lake

33

Water is a

solvent

34

Solvent

does the dissolving

35

Solute

-dissolves in solvent

ex. polar molecules, ions

36

HydroPHILIC

-dissolves in water

ex. salt, sugar

37

HydroPHOBIC

does NOT dissolve in water

ex. oil, fats

38

Acids

release H+ when dissolved in water

39

Base

accepts H+ when dissolved in water

40

Acidi pH #'s

0 - 7

41

Basic pH #'s

7 - 15

42

Neutral pH #

7

43

Buffers

-moderate changes in pH

-absorb or release H+

ex. bicarbonate/carbonic acid buffering system in blood

44

Neutrons =

atomic mass - atomic #

45

neutrons =

atomic mass - atomic #

46

Hbonds are ______ than covalent bonds

WEAKER

47

Mass is always the BIGGER...

# in periodic table

48

Hydrogen Bonds are usually...

-btwn 2 different molecules

49

______ bonds allow bugs to walk on water

hydrogen

50

Water is an example of ______ bond

Polar

51

Salt has _____bonds

Ionic