Chapter 2 Flashcards
1
Q
Chemistry
A
the study of interactions between atoms and molecules
2
Q
Atom
A
- the smallest unit of matter that enters into chemical reactions
- atoms interact to form molecules
3
Q
Atoms are composed of:
A
- Electrons- negatively charged particles
- Protons- positively charged particles
- Neutrons- uncharged/ neutral particles
- Protons and Neutrons are in the nucleus
- Electrons move around the nucleus (electron shell)
4
Q
Chemical elements
A
- each element has a unique number of protons
- there are the same number of protons and electrons in a neutral atom
- Atomic number= number of protons
- Atomic weight = number of protons and neutrons
5
Q
Atomic symbols
A
Hydrogen-H Carbon-C Nitrogen- N Oxygen- O Sodium- Na Magnesium- Mg Phosphorus- P
6
Q
Electronic Configurations
A
- electrons are arranged in electron shells corresponding to different energy levels
- each shell has a maximum number of electrons
- electrons fill the inner-most shells first
7
Q
How atoms form molecules
A
- atoms combine to form molecules
- a molecule that contains 2 or more types of atoms is called a compound: H20
- The “2” indicates that there are 2 atoms of hydrogen combined with 1 atom of oxygen
- molecules hold together because of attractive forces. called chemical bonds, between the atomic nuclei
8
Q
Chemical Reactions
A
- involve the making or breaking of bonds between atoms
- a change in chemical energy occurs during a chemical reaction
- Endergonic- reactions absorb energy
- Exergonic- reactions release energy
9
Q
Synthesis reactions
A
- occur when atoms, ions or molecules combine to form new, larger molecules
example: A + B –>(combines to form) AB (new molecule)
Anabolism: the synthesis of molecules in a cell
10
Q
Decomposition reactions
A
- occur when a molecule is split into smaller molecules, ions or atoms
example: AB –> (breaks down into) A + B
Catabolism: the decomposition reactions in a cell
11
Q
Organic vs inorganic compounds
A
Organic- always contain carbon and hydrogen
-example: C6H12O6
Inorganic- typically lack carbon
-example: CO2, Water, Oxygen gas
12
Q
Polar Molecule (water)
A
- whole molecule is neutral
- but, one end has a negative charge and the other end has a positive charge
13
Q
water
A
- life on earth evolved based on the chemistry of water
- inorganic
- water makes up 65-75% of cells, on average
- water more easily maintains a constant temperature than many other solvents; protects cells from temperature fluctuations
14
Q
acids, bases and salts
A
- dissociate into positively charged H+ ions and negatively charged ions
- dissociate into one or more H+ ion
example: HCI–> H+ + CI-
15
Q
Bases
A
- dissociate into negatively charged hydroxyl ions OH- and positively charged ions
- one or more OH- ion
example: NaOH –> Na+ + OH-
16
Q
Salts
A
- dissolves into water; does not produce hydrogen ions or hydroxyl
- dissociate into cations and anions, neither of which is H+ or OH-
example: NaCI –> Na+ + CI-
17
Q
pH scale
A
- most organisms grow best between ph of 6.5 to 8.5
- neutral pH= 7
- acidic pH= 0-6
- basic pH= 8-14
18
Q
functional groups
A
are responsible for most of the chemical properties of a particular organic compound
19
Q
Organic Compounds
A
- small organic molecules can combine into large macromolecules (large)
- macromolecules are polymers consisting of many small repeating molecules (many)
- the smaller molecules are called monomers (one)
20
Q
Major Macromolecules in Living Organisms
A
- carbohydrates
- proteins
- lipids
- nucleic acids
21
Q
Carbohydrates
A
- cell structures and energy sources
- consist of C, H and O
- Monosaccharides- are simple sugars with 3 to 7 carbon atoms
- Disaccharides- are formed when 2 monosaccharides are joined together
- Oligosaccharides- consist of 2 to 20 monosaccharides
- Polysaccharides- consist of tens or hundreds of monosaccharides joined together
- polymers of glucose that are covalently bonded differently
- starch is a plant storage product
- Glycogen is an animal storage product
- Cellulose is a structural compound in plants
- Chitin is a polymer of 2 sugars repeating many times
- hard substance in insect, crustacean, fungal cell walls etc.
- polymers of glucose that are covalently bonded differently
22
Q
Lipids
A
- primary components of cell membranes
- examples: fats, oils, waxes
- consist of C, H, and O
- are nonpolar and insoluble in water
23
Q
Simple lipids
A
- fats or triglycerides
- typically contain 1 glycerol molecule and 3 fatty acid molecules
- glycerol is a 3-carbon compound
- fatty acids contain long chains of carbons and are non-polar
- saturated fat- no double bonds
- unsaturated fat- one or more double bonds in the fatty acids
24
Q
Complex Lipids
A
- contain C, H, and O + P, N or S
- membranes are made of phospholipids
- phospholipids have 2 fatter aids and a phosphate group bonded to the glycerol molecule
- sterols (steroids)
25
Q
Protein
A
- are essential in cell structure and function
- function as
- enzymes that speed chemical reactions
- transporter proteins that move chemicals across membranes
- flagella are made of proteins
- some bacterial toxins are proteins
26
Q
Amino Acids
A
-proteins are polymers made of subunits
27
Q
Peptide bonds
A
- amino acids are joined by peptide bonds
28
Q
Levels of Protein Structure
A
-structure is important because the protein is not “active” or able to perform its function unless it is arranged in the correct structure
- primary structure- is a polypeptide cain (chain of amino acids)
- secondary structure- occurs when the amino acid chain folds and coils in a regular helix or pleats
- tertiary structure-occurs when the helix folds irregularly, forming disulfide bonds, hydrogen bonds, and ionic bonds between amino acids in the chain
- quaternary structure- consists of 2 or more polypeptides that are folded together
29
Q
Conjugated proteins
A
- consist of amino acids and other organic molecules bonded together
- glycoproteins- protein + carbohydrate
- nucleoproteins- protein + nucleic acid
- lipoproteins- protein + lipid
- many important compounds in the cell are conjugated proteins
30
Q
Nucleic Acids
A
- consist of nucleotides
- nucleotides consist of a
- pentose- 5 carbon sugar
- phosphate group
- Nitrogen-containing (purine or pyrimidine) base
31
Q
DNA
A
- deoxyribonucleic acid
- codes for genetic information in the cell
- has deoxyribose- type 5-carbon sugar
- exists as a double helix
- hydrogen bonds hold the two chains together
- nitrogen bases- adenine, cytosine, thymine and guanosine
- A bonds with T
- C bonds with G
32
Q
RNA
A
- Ribonucleic acid
- involved in protein synthesis in the cell
- has ribose- a type of 5-carbon sugar
- is single-stranded
- nitrogen bases- adenine, uracil, cytosine and guanine
- A bonds with U
- C bonds with G
33
Q
ATP
A
- Adenosine triphosphate
- has ribose, adenine, and 3 phosphate groups
- energy carrying compound in the cell
- Carries energy in the high energy bond of 3rd phosphate (2nd phosphate bond is also high energy)
- when bond is broken useful energy is liberated for the cell
