Test 1 multiple choice Flashcards
Carbon based molecules
- Proteins
- DNA, RNA
- Carbohydrtates
- Lipids
Why can carbon form diverse molecules
Forms 4 covalent bonds, bonds easilty to itself, valence of 4, tetrahedryl shape
How is structural and functional relatuonship determined
electron configuration
Determines kinds and numbers of bonds an atom will form
Isomers
same molecular formula, different sstructure
Types of isomers and explain each
- Structural: same molecular formula, different structure
- Cis-Trans: have the same covalent bonds but differ in spacial arrangement (cis: functional groups on the same side of the plane, trans: functional groups on different sides of the plane)
- Enantimers: mirror images
What is the significance of isomers
cells can distinguish between isomers. One can be an effective drug while the other can cause problems
What do carbohydrates include
sugars and polymers of sugars
What is a polymer
long molecule consisting of many similar building blokcs
Monosaccharides
What is it and example
classified by location of carbonyl group (aldose, ketose) and number of carbons (3-7)
Glucose: most common monosaccharide, major fuel for cells and building block for molecules
Disaccharides
Double sugars. Monosaccharides joined by dehydration synthesis
Gylcosidic linkage
covaalent bond created during dehydration synthesis
Polysaccharides
polymers of sugar, have storage and structural synthesis roles. Structure determined by sugar monomers and position of glycosidic linkages
Starch
polysaccharide consiting entirely of glucose monomers, plants
Glycogen
storage polysaccharide in animals
Cellulose
polysaccharide in cell walls of plants, made up of glucose molecules
Chitin
polysaccharide. exoskeleton components, made of glucose with nitrogen appendage
Lipids polar or nonpolar
nonpolar
Types of lipids
fats, phospholipids and steroids
Fats- types
Glycerol and fatty acids
Fatty acids (structure, types, function)
carboxyl group attached to long carbon skeleton
Saturated: max number of hydrogen atoms, no double bonds
Unsaturated: one or more double bonds
Function: store energy, adipose tissure storage
Phospholipids
components of cell membrane that assembe into bilayers
2 fatty acid tails (phobic) and one phosphate head group (philic)
Steroids
ex: cholestrol
4 fused rings
Component of cell membrane
Most important function of proteins
enzyme
what do enzymes do
act as catalysists, speed up reactions
Polypeptides
polymers built from amino acids, form proteins
Amino acid monomers
organic molecules with carboxyl and amino groups (acid and base)
R groups
side chains attached to the central carbon, determine unique characteristics
What are amino acids joined by
peptide bonds (covalent)
What are the four levels of protein structure
primary
secondary
tertiary
quarternary
Primary structure
amino acid sequence (linear)
seondary structure
coils and folds, found in most proteins (alpha helix and beta pleated sheet, stabilized by hydrogen bonds)
Teritary structure
interactions of R groups
Quarternary structure
Multiple polypeptide interactions (hemoglobin)
What causes sickle cell
a change in the primary structure of a protein, one amino acid change in hemoglobin
What can cause proteins to unravel, change shape. What does this mean for the protein
altertaions in pH, temperature, salt concentration
denatured, biologically inactive
Which organic moleculles can form polymers
proteins, carbs, nucleic acid
What are nucelic acids made of
monomers of nucleotides
Roles of DNA
provide instructions for replication, directs synthsis or mRNA, inherited from other cells
Roles of RNA
controls protein synthesis
Components of nucleic acid
- nitrogenous base
- pentose sugar
- phosphate group
Pyrimadines
CUT (6 membered ring)
Purines
AG (6 membered ring fuses with 5 membered ring)
Prokaryotic vs eukaryotic
Pro: no membrane bound organelles, smaller, archea and eubacteria
Eu: has membrane bound organelles, larger and more complex, protist, fungi, plant, animal, compartmentalized (allows for specialization)
What does RNA do for protein synthesis
protein translation
Nucleus parts
Nuclear envelope: encloses nucleus
Chromosome: DNA organized into desrcete units (always present but coil more at division)
Chromatin: uncoiled chromosomes
Nucelolus: site of rRNA synthesis
Ribosomes: made of rRna and proteins, protein synthesis
What is part of the endomembrane system
ER Nuclear envelope Golgi Lysosomes Vesicles (vacucoles)
Lysosome function
digestive enzymes (compartments), phagocytosis of virus, bacteria, worn out organelles etc.
Types of vacuoles
Food vacuole
Contractile vacuole
Central vacuole
Food vacuole
formed by pagocytosis
Contractile vacuoles
pump excess water out of the cells
Central vacuole
stores metabolites and water
Cytoskeleton
fibers extending through the cytoplasm
Parts of the cytoskeleton
Microtubules
Microfilliments
Intermediate fillaments
Microtubules
Thick
Transport mitochondria and vesciles. Help form extensions of cilia and flagella. Formation of mitotic spindle, synthesis of the cell wall (shape)
Microfilaments
Thinnest
Actin filaments.Help move myosin heads
Temporary pseudopod extensions
ameobic movement, cytoplasm streaming, mircovillus support
Intermediate filaments
diameter in the middle range
Built from keratin. Reinforce cell shape and fix organelle location. Made to bear tension
(ex: human skin, hair)
Extracellular matrix
what it is made of and what it does
cellulose fibers (rigidity), embedded in polysaccharides and protein
help things travel across the body, connects cells
What is the extracellular matrix in the plant cells
Cell wall (protects cell, shape, prevents excess water)
Parts of the ECM in animal cells
- glycoproteins: collegen, proteoglycans, fibronectin (bind to receptor proteins in the plasma membrane called integrins which relay messages from cell to cell)
- Junctions
Types of junctions in ECM
tight junctions
desmosomes
gap junctions
Tight junctions
membranes of neighboring cells pressed together. Prevents leakage
Desmosomes
fasten cells together in strong sheets (intermediate filaments)
Gap junctions
Provide cytoplasmic channels between adjacent cells. Portals of exchange for small solutes to cross from one cytoplasm to the next (communtication)
Gap junctions in plants
plasmodesmta
Fluid mosaic
membrane is fluid structure with mosaic of proteins embedded in it
Components of the plasma membrane
phospholipids, proteins, carbohydrates
Amphipathetic molecules
hydrophilic head, hydrophobic tail
Membrane proteins
Peripheral and integral
Peripheral proteins
bound to the surface of the membrane
Intergral proteins
what are they are functions
integrate through the lipid bilayer
- transport
- enzymatic activity
- signal transduction
- cell-cell recognition
- intercellular joining
- attachmment to cytoskeleton and ECM (shape)
Purpose of membrane carbohydrates and location
cel-cell recognition
external side of membrane, cells bind to them
bond to lipids (glycolipids), and proteins (glycoproteins)