Chapter 2 Flashcards
Chemistry
The science that deals with the structure of matter
Composition of matter
Atoms
Atoms
• definition
• what defines
Smallest stable unit of matter
•Types and arrangements of atoms define unique characteristics of matter
Atomic structure
•what does it include
3 subatomic particles (electrons, protons and neutrons)
Electrons
Occupy outer “shells”
Nucleus
• what does it include
• definition
- protons and neutrons
* determines mass of atom
Atomic number
Number of protons in an atom
• Usually atoms contain equal numbers of protons and electrons but not always
Chemical elements
A substance made up of 1 kind of atom
How many elements are there?
92 elements exist in nature
Principle elements of the human body
• 13
- Oxygen (O2)
- Carbon (C)
- Hydrogen (H)
- Nitrogen (N)
- Calcium (Ca)
- Phosphorus (P)
- Potassium (K)
- Sodium (Na)
- Chloride (Cl)
- Magnesium (Mg)
- Sulfur (S)
- Iron (Fe)
- Iodine (I)
Trace elements
- Only present in very small amounts
* 14 trace elements found in the body
Atomic mass
Total number of protons and neutrons in the nucleus of an atom
Isotope
• definition
• two kinds
• example
- Atom whose nuclei contain the same number of protons but differ in the number of neutrons
- stable and radioisotope
- Hydrogen has 3 isotopes
3 isotopes of hydrogen
- H= 1p+1e } stable isotope
- H= 1p + 1n + 1e }stable isotope
- H= 1p + 2n + 1e } radioisotope
Stable isotope
Nucleus of an atom does not emit subatomic particles spontaneously
Radioisotope
Nucleus of an atom emits subatomic particles spontaneously
How is matter combined?
By chemical bonds
How are chemical bonds formed?
Formed from interaction between 2 or more atoms
3 types of chemical bonds
- Ionic
- Covalent
- Hydrogen
Ionic bond
• What are they
• how are they created
- Ions: have unequal numbers of protons and electrons
* Bonds created by electrical attraction between cation and anions
Covalent bonds
• definition
• what forms single, double, or triple bonds
- Bond where 1 or more electrons are shared between atoms
* Depending on the number of electron pairs shared -will form single, double or triple bonds
Hydrogen bonds
- weak attractive forces
- attraction of partially positive charged hydrogen with a partially negative charged atom
- Important for changing the shape of molecules together
Molecule
• Definition
• 6 examples
Any chemical structure held together by covalent bonds • Hydrogen gas (H2) • Oxygen gas (O2) • Water (H2O) • Carbon dioxide (CO2) • DNA • RNA
Compound
• defintion
• 5 examples
- a chemical substance made of atoms of 2 or more different elements regardless of the type of bond joining them
- Sodium chloride (NaCl)
- Water (H2O)
- Carbon dioxide (CO2)
- DNA
- RNA
Two groups of compounds
- Inorganic
2. Organic
Inorganic compounds
•definition
•4 important classes
• Generally do not have carbon and hydrogen as principle structural elements and are small
- O2
- H2O
- CO2
- Acids, bases and salts
Organic compounds
• definition
• 4 important classes
• Always made from hydrogen and carbon (larger)
- carbohydrates
- lipids
- proteins
- nucleic acids
Water as an inorganic compound
- Most important molecule in your body
* Required for normal function of all physiological systems
What percentage of water are you?
Approximately 70% (2/3)
What role does water play in the human body?
• 4 things
- Maintains solubility of inorganic and organic molecules
- important for chemical reactions
- lubrication
- maintenance of body temperature
Acid •definition •what will strong acids do •what will weak acids do •example
- compound that dissociates (breaks apart) into water and releases hydrogen ions
- dissociate completely in H2O
- do not dissociate completely (H2CO3 H+ + HCO3)
- HCL -> H+ + Cl
Base
•definition
•what will strong bases do
•example
- compound that dissociates in water and releases hydroxyl groups; they remove hydrogen ions from solution
- will completely dissociate in H2O
- NaOH -> Na+ + OH-
Salt
•definition
•example
- compound that dissociates in water into cations and anions, neither of which is hydrogen ion or hydroxyl group
- NaCl -> Na+ +Cl
pH
•definition
•how many H+ ions are in H2O
A measurement of the hydrogen ion concentration of a fluid
• 0.0000001 mol/liter = [H+] =1 x 10 ^-7 mol/L
Which pH has the highest concentration of hydrogen ions?
pH 1 - the more acidic -> the highest concentration
pH in blood
•what is it
•why is pH maintenance important for homeostasis?
- 7.35 - 7.45
* blood pH below 7 can cause coma and death
Buffers •definition •what does it involve •example •what does it produce
- Compounds that help to maintain pH of body fluids by removing or replacing hydrogen ions
- an acid and base
- HCl + NaOH -> NaCl + H2O (salt water)
- neutral solution
4 classes of organic compounds
- carbohydrates
- lipids
- protein
- nucleic acids
Carbohydrates •% of body weight •component elements and ratio •3 examples •function
- 1% (sugars and starches)
- C H O; 1:2:1
- monosaccharides, disaccharides and polysaccharides
- energy sources
Monosaccharides
•definition
•how many carbon atoms
•__ carbon sugar
- simple sugar
- 3-7
- 6
Disaccharides •definition •example •how do you form one •how do you break one apart
- 2 monosaccharides joined together
- glucose + fructose = sucrose
- dehydration synthesis
- hydrolysis
dehydration synthesis
removal of water to create bond
hydrolysis
addition of H2O to break bond
Polysaccharides
•definition
•3 examples
- more complex carbohydrates; can be straight of branched
* cellulose, starch, glycogen
cellulose
component of plants that cannot be broken down
starch
glucose storage in plants
glycogen
glucose storage in animals
Lipids •% of body weight in men;women •component elements; C to H ratio •what does it contain less of •5 classes
•12-18%;18-24% •C H O; 1:2 •oxygen 1. fatty acids 2. eicosaniods 3. triglycerides 4. phospholipids 5. steriods
Fatty acids
•definition
•2 types
- long carbon chain with hydrogen atoms attached; has a carboxyl acid group
- saturated and unsaturated
Saturated fat
•how many covalent bonds in each carbon
• what is it like at room temp
•alot or a little hydrogen
- 4 single covalent bonds
- solid
- contains the max amount of hydrogen
Unsaturated fat •definition • alot of a little hydrogen •what is it like at room temp •2 types
- one or more single covalent bonds replaced with a double bond
- not max loaded with hydrogen
- liquid at room temp
- monounsaturated and polyunsaturated
Monounsaturated
- describes number of bonds
* 1 double bond
Polyunsaturated
•more than 1 double bond
Eicosaniods
•example
•structure
•function
- prostaglandin
- short fatty acids and 5 of the carbon atoms form a ring
- coordinate or direct local cellular activities
Tryglycerides •definition •structure •what is it stored as •3 functions
•fat • 1 glycerol (backbone), 3 fatty acids • lipid droplets in adipose tissue 1. Energy 2. insulation 3. protection
Phospholipid
•structure
•function
- Phosphate group is substituted for 3rd fatty acid
* forms bi layer of cell membranes
Steroids
•structure
•2 functions
•large lipid molecules, complex 4 ring structure
- maintenance of cell membrane
- produces hormones (estrogen and testosterone)
Protein•• •definition •% of body weight •component elements •building blocks
- long chains of AA linked together by dehydration synthesis
- 20%; most abundant
- C H O N (may contain sulfur and phosphorus)
- Amino acids
Amino acids
•how many naturally occurring
• 5 components
• 20
- central carbon
- hydrogen
- amino group
- carboxylic acid group
- R group (determines the AA)
Peptide
•where are they located
•defintion
- in proteins
* molecules of AA held together by peptide bonds
Polypeptides
more than 100 AA linked together to form a protein
Folding of a protein
• 3 steps
- Primary structure
- secondary structure
- tertiary structure
- quaternary structure
Primary structure
linear chain of amino acids
Secondary structure
Based on H - bonding between AA
• can either be alpha-helix or beta pleated sheet
Tertiary structure
Interactions between polypeptide and H2O cause complex folding
•includes hydrophobic and hydrophobic
•formation of disulfide bonds which creates permanent loops and coils
Quaternary structure
•definition
•3 examples
- caused by interaction between one or more polypeptide chains to form a complex
- hemoglobin (globular), keratin or collagen (fibrous)
Enzymes
•definition
•3 steps
• biological catalysts that catalyze reactions that sustain life
; accelerate chemical reactions without being permanently changed or consumed
1. substrate binds to active site
2. substrate fits in to active site (lock and key) to form enzyme-substrate complex
3. Product is released and enzyme is ready for new substrate
3 important characteristics of enzymes
- specificity: only catalyzes one type of reaction
- saturation limit: rate of reaction is dependent on concentration of substrate and enzyme
- regulation- enzyme activity is regulated
Nucleic Acids
• Component elements
• two types
- carbon, hydrogen, oxygen, nitrogen, phosphorus
* deoxyribonucleic acid (DNA) and Ribonucleic acid
Dexoyribonucleic acid • what does it affect • building blocks •what makes up DNA • how many carbons are in the sugar •why is called deoxy
- affects all aspects of body structure and function
- nucleotides
- Nitrogenous base, sugar, phosphate
- 5
- Missing O2 on carbon 1
Nitrogenous bases
- Purines (2 rings): Adenine and guanine
2. Pyrimidines (1 ring): Cytosine and thymine (DNA only)
Waston and Crick theory
Double helix is much like a twisted ladder
•uprights=alternating phosphate and sugar groups
•rungs= pairs of nitrogenous bases
What does a hydrogen bond do in DNA?
Links nitrogenous bases together
Ribonucleic Acid •building blocks •what makes up RNA •structure •3 types of RNA
- Nucleotides (Adenine, Guanine, Cytosine, Uracil)
- Nitrogenous bases, sugar, phosphate
- Single strand of nucleotides connected through alternating sugar phosphate groups;shapes can be complex
- Messenger (mRNA), Transfer (tRNA), Ribosomal (rRNA)
How do cells power energy requiring reactions
By ATP
ATP
•what does it stand for
•What is adenosine made up of
- Adenosine Triphosphate
* Adenine and ribose
ATP hydrolysis •definition •what does it require •formula •what can it be used for
•Breakdown of ATP
•requires an enzyme - Adenosine triphosphatase (ATPase)
ATP -> ADP + P + Energy
• can be used to drive reactions that consume energy
3 examples of reactions that uses ATP hydrolysis
- Muscular activity
- Cellular transport activity
- Formation of macromolecules through various chemical reactions