Feralis Bio Flashcards
Atom
made up of neutrons, electrons, and protons
Molecules
group of 2 or more atoms held together by a chemical bond
chemical bonds
due to electron interactions
Electronegativity
the ability of an atom to attract electrons
Ionic Bonds
transfer of electrons from one atom to another (different electronegativities)
Covalent Bonds
electrons are shared between atoms (similar electronegativity)
-can be single, double, or triple bonds
Nonpolar covalent bonds
equal sharing of electrons
-identical electronegativity
Polar Cavalent bonds
unequal sharing of electrons
-different electronegativity and formation of a dipole
Hydrogen bonds
weak bond between molecules with a hydrogen attached to a highly electronegative atom and attracted to a negative charge on another molecule (has to be N, O , or F)
Properties of water
- excellent solvent: dipoles of H2O break up charged ionic molecules
- High Heat capacity: the temp of large water body are very stable in response to temperature changes of surrounding fair; must add large amount of energy to warm up water. High heat of vaporization as well
- ICE FLOATS: water expands as it freezes, becomes less dense the its liquid form (H-bonds become rigid and form a crystal that keeps molecules separated)
- COHESION/SURFACE TENSION: attraction between like substance due to H-bonds: the strong cohesion between molecules produces a high surface tension
- ADHESION: attraction of UNLIKE substances (wet finger and flip pages); capillary action of liquid to flow without external forces (against gravity)
Functional Group
a particular cluster of atoms
-give molecules unique properties
Hydroxyl
properties
(-OH)
- polar
- hydrophilic
Carboxyl properties
- COOH
- polar
- hydrophilic
- weak acid
Amino properties
NH2
- polar
- hydrophilic
- weak base
Phosphate properties
PO3
- polar
- hydrophilic
- acid
Carbonyl properties
(C=O)
- polar and hydrophobic
- aldehyde
- ketone
Methyl
CH3
- nonpolar
- hydrophobic
Monosaccharide
-Type of Carbohydrate
-single sugar molecule (ex: glucose and fructose)
-alpha or beta based on position of H and OH on first carbon
(down=alpha, up=beta)
Disaccharide
-type of carbohydrate
-two sugar molecules joined by a glycosidic linkage (joined by dehydration)
-Ex: Sucrose (glucose + fructose)
or Lactose (glucose + galactose) + Maltose (glucose + glucose)
Polysaccharide
- type of carbohydrate
- series of connected monosaccharides
- polymer
- bond via dehydration syntehsis
- breakdown via hydrolysis
Starch
a polymer of alpha-glucose molecules
-stores energy in plant cells
Glycogen
- a polymer of alpha-glucose molecules
- store energy in animal cells
- differ in polymer branching
Cellulose
- a polymer of Beta-glucose
- structural molecules for walls of plant cells and wood
Chitin
- polymer similar to cellulose, but each Beta glucose has a nitrogen-containing group attached to ring
- structural molecule in fungal cell walls (also exoskeleton of insects etc.)
Lipids
- hydrophobic molecules
- functions: insulation, energy storage, structural (cholesterol and phospholipids in membrane), endocrine
Triglycerides
- type of lipid
- three fatty acid chains attach to a glycerol backbone
Saturated Triglyceride
no double bonds
- bad for health
- saturated= straight chain= stack densely and form fat plaque
Unsaturated Triglyceride
double bonds
- better for health
- unsaturated=double bonds cause branching= stack less dense
Phospholipid
- type of lipid
- two fatty acids and a phosphate group (+R) attached to glycerol backbone
- AMPHIPATHIC
Amphipathic
both hydrophobic and hydrophilic properties
Steroids
three 6 membered rings and one 5 membered ring
-hormones and cholesterol(membrane component)
Wax
- lipid derivative
- esters of fatty acids and monohydroxylic alcohols
- use as protective coating or exoskeleton
Carotenoids
- lipid derivative
- fatty acid carbon chains with conjugated double bonds and six membered C-rings at each end
- pigments which produce colors in plants and animals– carotenes and xanthophylls (subgroups)
Porphyrins
- lipid derivatives
- tetrapyrroles
- 4 joined pyrrole rings
- often complex with metal
Adipocytes
- specialized fat cells
- white fat cells contain a large lipid droplet composed primarily of triglycerides with a small layer of cytoplasm around it
- Brown fat cells have considerable cytoplasm, lipid droplets scattered throughout, and lost of mitochondria
Glycolipids
-are like phospohlipids but with carb group instead of phosphorus group.
How are lipids transported in the blood?
lipids are insoluble thus they are transported via lipoproteins (lipid core surrounded by phospholipids and apolipoproteins)
Storage Protein
- casein in milk
- ovalbumin in egg whites
- zein in corn seeds
Transport Proteins
Hemoglobin carries oxygen
cytochromes carry electrons
Enzymes
- amylase catalyzes the reaction that breaks the alpha-glycosidic bonds in starch
- catalyzes a reaction in both forward and reverse directions based on substrate
- -efficiency is determined by temp and pH
- cannot change spontaneity of a reaction
- ALWAYS CONSIDERED TO BE PROTEINS, but sometimes RNA can act as an enzyme Ribozyme
Cofactor
nonprotein molecules that assist in enzymes.
- can be organic (called coenzymes ex: vitamin) or inorganic (metal ions Fe2+ and Mg2+)
- if cofactor strongly covalently bonds to enzymes its called a prosthetic group
Globular Proteins
- somewhat water soluble
- many functions: enzymes, hormones, inter and intracellular storage and transport, osmotic regulation, immune response etc.
- mostly dominated by tertiary structure
Fibrous/structural proteins
not water soluble
- made from long polymers
- maintain and add strength to cellular and matrix structure
- mostly dominated by secondary structure
Membrane Proteins
membrane pumps/channels/ receptors
Protein Denaturation
The secondary and tertiary structure of the protein is basically removed, but not necessarily means that the protein is broken down into individual amino acids
-usually irreversible
nucleoside
sugar + Base
Nucleotide
nitrogen base, five carbon sugar deoxyribose, phosphate group
Purines
- 2 rings
- adenine and guanine
- 2 Hydrogen bonds
Pyrimidines
- 1 ring
- Thymine, cytosine
- 3 hydrogen bonds
Cell doctrine/theory
- all living organisms are composed of one or more cells
- the cell is the basic unit of structure, function, and organization in all organisms
- all cells come from preexisting, living cells
- cells carry hereditary information in the form of DNA
RNA world hypothesis
proposes that self-replicating ribonucleic acid (RNA) molecule were precursors to current life (based on deoxyribonucleic acid (DNA), RNA and proteins).
- RNA stores genetic information like DNA and catalyzes chemical reactions like an enzyme protein
- may have played a major step in the evolution of cellular life
- RNA is unstable compared to DNA, so more likely to participate in chemical reactions (due to its extra hydroxyl group)
Central Dogma of Genetics
biological information cannot be transferred back from protein to either protein or nucleic acid
DNA-> RNA-> Proteins
Stereomicroscope
visible light for surface of sample
-can look at living samples, but low resolution versus compound light microscope
Compound Microscope
- visible light for thin section of sample
- can look at SOME icing samples (single cell layer)
- may require staining for good visibility
Phase contrast
- uses light phases and contrast
- allows for detailed observations of living organisms (including internal structures) if thin
- Good resolution/contrast, but not good for thick samples and produces “halo effect” around perimeter of samples
Confocal Laser scanning and fluorescense
- can look at thin slices while keeping sample intact.
- can look at specific parts of the cell via fluorescent tagging
- can look at living cells, but only fluorescently tagged parts
- Fluorescence can cause artifacts
- -used to observe chromosomes during mitosis
**confocal laser scanning microscope can be w/out fluorescence as well. Uses laser light to scan dyed specimen, then displays the image digitally