Chapter 2 Flashcards
Electronegative
Measure of the tendency of an atom to attract an electron.
Ex. F+K –> F steals e- from K
F+F –> share electrons
Electropositive
Measure of an elements ability to donate/lose an electron.
Ionic Bond
- gain or loss of electrons
- attraction between neg & pos e-
- dissociate in water
Covalent Bond
What is needed to break them apart??
- Sharing of electrons
- strong bonds
- require enzymes to break
Polar Covalent
-unequal sharing of electrons
Ex. Between the O & H in water molecules because the O is slightly neg & H is slightly positive.
Non-Polar Covalent
Equal sharing of electron
Hydrogen Bond
- hydrogen atom in a polar molecule is attracted to electronegative atom in same molecule or another polar molecule
- weakest bond
Ex. Between the O & H of separate water molecules
Water
- polar molecule
- excellent solvent
H2O–> OH + H+
Hydrophilic
Water loving
Hydrophobic
Water hating
pH
- based on concentration of hydrogen
- less hydrogen —> more acidic
Functional Groups
- determine the characteristics for a chemical reaction
- highly electronegative
Adenosine Triphosphate (ATP)
- energy currency of a cell
- negatively charged phosphate groups repel each other and weak bonds are broken to release energy
Macromolecules
Large molecules
4 major classes of macromolecules
- Proteins
- Carbohydrates
- Nucleic Acids
- Lipids
Monomer examples:
Protiens, carbohydrates, nucleic acid, or lipids.
Polymer
Monomers combined through dehydration synthesis
Dehydration synthesis
Process that makes complex molecules out of simple molecules by removal of water to create bonds.
Hydrolysis
Addition of water to break bonds
Functions of Protiens
- enzymes (catalyze reactions)
- transport molecules
- move cells
- provide cellular framework
- sense & respond to conditions outside cell
- regulate gene expression
Properties of Protiens
- made up of Amino Acids
- infinite combinations of 20 amino acid
- protein shape determined by amino acid sequence
What makes up a protein?
- amino acid group
- carboxyl group
- carbon
- unique side chain
Peptide Bonds
-hold amino acids together through dehydration synthesis
4 Protein Structures:
- primary
- secondary
- tertiary
- quaternary
Temperature’s affect on protein:
Higher temp causes proteins to lose their shape because it breaks apart hydrogen bonds
Carbohydrates are made up of?
Polymers:
- glucose
- starch
- cellulose
DNA & RNA
Monosaccharides are…
Made up of chains of polysaccharides
Disaccharides are
Made up of two monosaccharides joined by covalent bond
Ex. Sucrose (glucose+fructose)
Maltose (glucose+glucose)
Nucleic Acids
- made up of single unite nucleotides
- ribose: adenine, guanine, cytosine, & uracil
- deoxyribose: adenine, guanine, cytosine, thymine
Nucleotides are held together by
Covalent bonds between one nucleotide’s phosphate group & the sugar of the next
Lipids
- non polar
- hydrophobic
- do not dissolve in water
Glycerol + 3 fatty acids are combined through dehydration synthesis to create
Triglycerides
Glycerol + 2 fatty acids + phosphate group =
Phospholipid
Makes up cell membrane
Saturated fats
No double bonds
Unsaturated
Double bonds
Phospholipids contain
Hydrophilic head & hydrophobic tail
Lipids include…
- phospholipids
- steroids
- mycolic acid
- triglycerides
- waxes
- cholesterol
Characteristics of Steroids?
Give an example of a steroid and its function:
- hydrophobic
- simple lipids
- four ring structure
Ex. Sterol (adds me brain stability)
