Introduction to chemistry

Question 1

Define chemistry

Answer 1

field of science dedicated to the study of matter.

Question 2

Define matter

Answer 2

everything that has mass and voluume

Question 3

Smallest unit of matter

Answer 3

atom

Question 4

Components of an atom

Answer 4

protons and neutrons = nucleous
electrons orbit around

Question 5

How to calculate atomic mass

Answer 5

sum of protons (atomic number) and neutrons

Question 6

how to calculate neutrons

Answer 6

substract protons (atomic number) form atomic mass

Question 7

how to see an atom

Answer 7

because of their size they require specialized microscope to be seen

Question 8

neutral atom

Answer 8

equal number of protons and electrons

Question 9

define element

Answer 9

substance that cannot be broken down into any simpler substance

Question 10

chemical element

Answer 10

pure substance, made of a single type of atom

Question 11

Parts of elements

Answer 11

atomic number
atomic mass
isotopes (depends)
symbol

Question 12

Define neutral element

Answer 12

has same quantity of protons, neutrons and electrons

Question 13

Atomic symbols can be

Answer 13

english, greek or latin

Question 14

Define isotope

Answer 14

only seen in some tables and identifying when an atom has different amounts of protons and neutrons

Question 15

How many elements are in the periodic table

Answer 15

118 (92 found in nature, the rest made in labs)

Question 16

Define compounds

Answer 16

other pure substance, combinations between elements mostly found in nature (example H2O)

Question 17

Chemical compound

Answer 17

formed by a chemical combination of two or more elements. represented by chemical formulas ( xample sodium cloride - NaCl)

Question 18

Types of compounds

Answer 18

covalent and ionic

Question 19

Define bond

Answer 19

force which joins the atoms in compounds toguether

Question 20

Types of bonds

Answer 20

ionic
covalent
metalic
hydorgen

Question 21

Describe ionic bond

Answer 21

electrons are transfered between atoms to form ionic compounds, one metal and the other non metal. The atoms join toguether, gaining and loosing electrons, becoming ions

Question 22

Describe covalent bonds

Answer 22

electrons are shares equally between non - metal elements, electrons will travel between the atoms which are joined toguther, also known as molecules

Question 23

Describe metalic bond

Answer 23

electrons will jump bac and fourth from one atom to the other, the atoms will be separated, only occurs with two metal elements.

Question 24

Describe hydorgen bond

Answer 24

only occurs when a hydorgen atom and another atom stick toguether, like in the water molecule, considered the strongest type of bond

Question 25

Define metabolism

Answer 25

the combination of chemical changes that occur in an organism to produce energy and materials which cells need to stay in optimal conditions and carry out their lively functions. helps eliminate toxic substances.

Question 26

Define biochemical processes

Answer 26

living thins carry theses out in order to grow, develop reproduce and others

Question 27

Define chemical reaction

Answer 27

combination of two or more substances to form completely new substances. its made up of reactants and products.

Question 28

Define reactant

Answer 28

substances which start the chemical reaction

Question 29

Define product

Answer 29

result of the reaction or combination of ractants. Since matter cannot be created or destroyed, the product of a combination of reactants will have the same quantity of them summed up.

Question 30

What happens in all chemical reactions

Answer 30

chemical bonds are broken, reorganized and rearranged to form new substances, which involves changes in energy. If they release energy, its considered a exothermic reaction and if they gain it, there considered endothermic

Question 31

Chemical reactions in organism are divided in

Answer 31

anabolic and catabolic

Question 32

Define anabolic reactions

Answer 32

where energy is consumed, the reaction starts with a small molecule which increases in size, considered endothermic. example - photosynthesis and protein synthesis.

Question 33

Define catabolic reactions

Answer 33

decomposition reactions, energy is released making the molecule go from lager to smaller, considered exothermic. example - cellular respiration and digestion

Question 34

Define catabolic processes

Answer 34

where complex organic molecules are degrated.

Question 35

Define activation energy

Answer 35

stimulus or energy needed for a chemical reaction to start.

Question 36

Define catalyst

Answer 36

substance that accelerates the reaction rate by reducing the activation energy of the chemical reaction, they are not consumed by the chemical reaction and dont change its equlibrium contstant.

Question 37

Define enzymes

Answer 37

biochemical catalysts, they are all considered proteins but not all proteins are enzymes. With the use of enzymes, the activation energy of the reaction will decrease, meaning the product will form faster though it will not be different than without the use of the catalyst.

Question 38

Define substrate

Answer 38

where the enzymes act on, enzymes are very specific than other inorganic catalysts, they will only act on a single or reduced group of these.

Question 39

How does the process of an enzyme catalyzing a reaction occur?

Answer 39

the substrate will bind to the active site, its center can be binding or catalytic, when the product forms, the enzyme can move to catalyze another substrate.

Question 40

Define active site

Answer 40

region of the enzyme which the substrate binds to be catalyzed

Question 41

models of how the substrate binds (explanation)

Answer 41

lock and key (Fischer's) - the structure of the substrate and active site are complementary. induced fit (Koshland's) - the active site adopts the form (shape) only in the presence of the substrate.

Question 42

Factors that influence catalyst activity

Answer 42

Ph - bc protein conformation partly depends on its electric charge. Temperature - bc certain temperature can cause them to denaturate. Cofactor - helps biochemical transformations Ionic stregth - what the active site is usually made of . Inhibitions - there are four types.

Question 43

Define molecule

Answer 43

part of a substance which retains all of its properties