bio- biochem Flashcards
Proton
Positively charged subatomic particle in an atoms nucleus
8 Characteristics of life
Made of cells Use energy Ability to reproduce Respond to stimulus Maintain homeostasis Grow and develop Have DNA Change and evolve over time
Neutron
Neutral subatomic particle in an atoms nucleus
Electron
Negatively charged subatomic particle in electron shells
Covalent bonds
When two atoms share their valence electrons and overlap their electron orbitals in order to complete the outermost orbital shell
Valence electrons
Electrons in the outer shells that are used to covalently bond
What makes a molecule organic?
The elements in it are covalently bonded Usually big Associated with living systems ALWAYS contain carbon SHNOPSi is commonly found in it
SHNOPSi
Sulfur Hydrogen Nitrogen Oxygen Phosphorus Silicon
Inorganic
Carbon dioxide and other molecules without carbon
Carbon
Has 6 total electrons (4 valence)
Can form chains or rings (when it bonds)
Versatile
How many elements can carbon potentially covalently bond with?
4 because it has 4 electrons in its outermost shell but can hold up to 8 in that shell– can bond with 4 other atoms to get 8
Can form single, double, or triple bonds, or rings
What are Functional groups?
Cluster of atoms that determines the chemical reactivity and other characteristics of a molecule
Name the functional groups
Hydrogen Hydroxyl Carboxylic acid Amino Phosphate Methyl
Hydrogen group
-H
Polar or nonpolar (depending on which atom it is bonded to)
Involved in dehydration and hydrolysis reactions
Found in: almost all organic molecules
Hydroxyl group
-O-H
Polar
Involved in dehydration and hydrolysis reactions
Found in: carbs, nucleic acids, alcohols,some acids, steroids
Carboxylic acid group
=O
-C
-O-H
Acidic
Involved in peptide bonds
Found in: amino acids, fatty acidsAmino group
-H
-N
-H
Basic
May bond an additional H+ to become positively charged
Involved in peptide bonds
Found in: amino acids, nucleic acids
Phosphate group
H
O
-O-P=O
O
H
Acidic
Links nucleotides in nucleic acids
Energy-carrier group in ATP
Found in: nucleic acids, phospholipidsMethyl group
H -C-H H Nonpolar Tends to make molecules hydrophobic Found in: many organic molecules, especially common in lipids
Polar
Has opposite poles (ex: water)
Give away- one side has oxygen
Electronegativity
Attracts electrons to its outer shell bc its v close to becoming stable (full electron outer shell)
But shares it evenly, doesn’t steal them
Ex: oxygen has 6 valence electrons, only 2 away
Macromolecules
Huge molecules made up of smaller molecules
Macro=giant
Formed thru polymerization reactions
Monomers
Subunit
Make up polymers
Polymer
Multiple (3+) monomers together
Dimer
2 monomers
Polymerization reactions
Dehydration synthesis and hydrolysis
Dehydration synthesis/ condensation
Anabolic reaction
Monomers join together by removing a water molecule (H2O)
Partial negative end attracted to atrial positive end
Hydrolysis
Polymers broken down by breaking a water molecule into -H and -H-O and adding it to break the bond between monomers
4 categories of biological molecules
Carbohydrates
Lipids
Proteins
Nucleic acids
Carbohydrate composition
C, H and O in ratio of 1:2:1
Ex: glucose is C6H12O6
Monosaccharides
Simple or single sugars
Disaccharides
Two linked monosaccharides
Polysaccharides
Long chains of monosaccharides
Isomer
Molecules with the same molecular formula but a diff structure
What’s the only group of biomolecules that’s isometric?
Carbohydrates
Ex: C6H12O6 = fructose and glucose, but they have diff structures
Structure of monosaccharides
Back bone of 3-7 carbon atoms
Many -OH And -H functional groups
Ring shaped
Fate of monosaccharides inside a cell
Broken down for energy
OR
linked together by dehydration synthesis
Why are most small carbs water soluble
They have polar -OH functional groups
Sucrose (table sugar)=
Glucose+fructose
Lactose (milk sugar)=
Glucose+galactose
Maltose (malt sugar)=
Glucose+ glucose
2 types of polysaccharides
Storage polysaccharides
Structural polysaccharides
Starch
Storage polysaccharide in plants
Polymer of glucose
Formed in roots and seeds as a form of glucose storage
Glycogen
Storage polysaccharide in animals
Polymer of glucose
Found in liver and muscles
Cellulose
Structural polysaccharide in plants
Polymer of glucose – each alternate glucose is inverted
Found in cell walls of plants and some fungi
Why are cell walls indigestible for most animals?
Made of cellulose
The orientation of the bonds between glucose in cellulose (one is right side up, next is upside down, …) –inverted pattern
Chitin
Structural polysaccharide in plants and animals
Polymer of modified glucose units
Found in outer coverings of insects, crabs, and spiders
Found in cell wall of some fungi
Lipids
Large chains of nonpolar hydrocarbons
Hydrophobic and water insoluble
Major 4 functions of lipids
Long term energy storage
Waterproofing
Membranes in cells (ex: phospholipids)
Hormones (ex: estrogen and testosterone)
Fats and oils - structure
3 fatty acid subunits + glycerol join by dehydration synthesis to make a triglyceride
Fats and oils-purpose
Long term energy storage
What stores more energy- lipids or carbs? And why
Lipids – more energy rich/ energy condensed than carbs
Saturated fats
Solid at room temperature
Fit as many hydrogens as possible
Mostly SINGLE bonds
fatty acid tails are straight
Problem with Saturated fats
Can become a plaque and stop your blood flow
Unsaturated fats
Liquid at room temperature
Less hydrogen atoms
DOUBLE bonds– makes kinks in the tails
Problem with unsaturated fats
Unsaturated trans fats have been linked to heart disease
Waxes
Long hydrocarbon chains
Strongly hydrophobic
Highly saturated
Waxes-purpose
Form waterproof coatings and build honeycomb structures
Examples of where waxes are used
Waterproofing:
Leaves and stems of plants
Fur in mammals(especially marine)
Insect exoskeletons
Phospholipids
Form plasma membranes around all cells
Phospholipid structure
2 fatty acids + glycerol + short polar functional group
What is special about phospholipids (in terms of water solubility)?
It has polar heads (functional group) which are hydrophilic
And nonpolar fatty acid tails which are hydrophobic
Steroid structure
Four carbon rings fused together
Steroids examples
Cholesterol (found in membranes of animal cells)
Male and female sex hormones
Most important biomolecules
Proteins
Protein function
Structure Movement Defense Storage signaling Catalyze reactions (most important)
Examples of structural proteins
Collagen in skin
Keratin in hair, nails, and horns
Examples of movement proteins
Actin and myosin in muscles
Examples of defense proteins
Antibodies in bloodstream
Examples of storage proteins
Albumin in egg white
Example of signaling protein
Growth hormone in bloodstream
Example of catalyzing proteins
Enzymes
Protein composition
Chains of amino acids joined by dehydration synthesis
Amino acid structure
R group
Amino group-O-carboxylic acid group
H
R Group in amino acids
Variable group, differs in every amino acid
Some are hydrophobic some are hydrophilic
If the R group is a cysteine..
Can form disulfide bridges
How are amino acids joined together to create a protein?
Dehydration synthesis creates a peptide bond between the carbon (from carboxylic acid group) and the nitrogen (amino group) of adjacent amino acids
O-H from carboxylic acid group and H from amino group are taken out as water
Importance of amino acids
The sequence, type, position, and number of amino acids determines the proteins structure and function
What happens if the positioning of R groups is disrupted?
Certain bonds will not be made which will lead to denaturing the protein (loss of function)
4 levels of protein structure
Primary
Secondary
Tertiary
Quaternary
Primary structure
Sequence of amino acids linked together in a protein
Secondary structure
Helices and pleated sheets
Tertiary structure
Complex folding of the protein chain held together by disulfide bridges, hydrophilic/hydrophobic interactions, and other bonds
Quaternary
Multiple protein chains are linked together
Nucleotides
Make up nucleic acids
Nucleotide structure
Phosphate group-5 carbon sugar-nitrogen containing base
Two types of nucleotides
Ribonucleotides (A,G, C, U) found in RNA
Deoxyribonucleotides (A,G,C,T) found in DNA
Two types of nucleic acid polymers
DNA found in chromosomes (carries genetic info needed for protein construction )
RNA (copies of DNA used directly in protein construction)
Other nucleotides (diff purposes )
Nucleotides as intracellular messengers
…as energy carriers
…as enzyme assistants
Nucleotides as intracellular messengers
Cyclic nucleotides carry chemical signals between molecules
Nucleotides as energy carriers
ATP carries energy stored in bonds between phosphate groups
NAD+ and FAD carry electrons
Nucleotides as enzyme assistants
Coenzymes help enzymes promote and guide chemical reactions
Anabolic reactions
Building up reaction
Reactant + reactant -> product
Catabolic reactions
Breaking down reaction
Reactant -> product + product
Activation energy
The amount of energy needed to start a reaction
What happens when chemical bonds form or break?
Energy is either released if absorbed
Do anabolic reactions absorb or release energy ?
Absorbs - needs a constant energy source (endothermic)
Look at graph in ppt
Do catabolic reactions absorb or release energy?
Release- spontaneous reactions (but will need a spark or something to start it)
Exothermic
Look at graph in ppt
Where do we get energy needed for absorbing (anabolic) reactions?
Humans- food
Plants- sunlight
Catalyst
Speeds up rate of chemical reaction
Lowers activation energy
Enzymes
Proteins that speed up chemical reactions ( by providing a substance for it to occur on)
How are enzymes specific?
Enzymes and substrates (reactants) are made for each other like lock (enzyme) and key (substrate)
How are enzymes named?
Named after their function + “ase”
Ex: DNA polymerase
Substrate
Reactant
What the enzyme will change
Active site
Place on enzymes where substrates bind
Enzyme-substrate complex
When enzyme and substrate binds together
Denaturing an enzyme
Changing and enzymes shape
Anything that influences a chemical reaction: pH Temperature Regulatory proteins Inhibitors
What affects enzymes?
