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Flashcards in Biology 2: Biochem Deck (57)
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1

Molecule

2 or more atoms joined together.

2

Atoms bond with other atoms...

to become more stable and to fill their outer energy levels

3

Ionic Bond

one atom "steals" electron from another

4

Covalent Bond

atoms "share" electrons

5

Polar Molecule

molecule with a positive and a negative end
it's atoms do not share electrons equally

6

Hydrogen Bond

the hydrogen (positive) end of a polar molecule is attracted to the negative end of another molecule
(often O or N)

7

Cohesion

polar water molecules are attracted to each other, and this creates surface tension

8

Adhesion

polar water molecules are attracted to other polar molecules

9

Surface Tension

caused by cohesion, "skin" on the surface of water

10

Cohesion + Adhesion

keeps molecules organized inside cells
allows H2O to move against gravity in plants

11

Temperature Moderation

adding heat makes molecules "twitch" faster
hydrogen bonds moderate movement
areas near water have a more stable climate
evaporation helps organisms maintain homeostasis

12

Low density of ice

lose thermal energy => molecules slow down => H bonds lock them in place in a grid => molecules are farther apart, so they are less dense and the ice floats

13

Water is good at dissolving because...

it's polar!

14

Solution

uniform combination of two or more substances

15

Solute

thing that gets dissolved

16

Solvent

thing that does the dissolving (pulls ions away)

17

Polar charges...

on H2O molecules are attracted to charted regions of other polar molecules

18

For something to dissolve,

the attraction to water must be greater than the attraction to itself

19

The solvent used by organisms...

water

20

In solutions...

a few H2Os split into ions

21

Acids

pH<7 add H to solution

22

Bases

pH>7 remove H from solution

23

Buffers

substances that help organisms maintain pH homeostasis

24

Carbohydrates Composition

2 Hydrogen, 1 Oxygen, 1 Carbon

25

Carbohydrates Root

Sugar molecules

26

Examples of Carbs

Pasta and potatoes

27

Starch

source of energy, basic element of diet, animal energy storage

28

Monosaccharide

a single sugar unit (glucose)

29

Disaccharide

two monosaccharides (sucrose)

30

Polysaccharide

many monosaccharides