Bio quiz 1 revision Flashcards
General cell size?
1-100microns
Difference between animal & plant cells?
Plants contain: cell wall, chloroplasts, central vacuole, rarely poses cilia
Basic cell structure of prokaryotes…?
characteristic of bacterial cells NO nucleus (DNA nucleoid) NO membrane-bound organelles very small (<5 microns diameter) almost always have cell wall some have flagella (NEVER cilia) Also may contain: plasmid, capsule or slime layer, pili, ribosomes, food granules, plasma membrane, cytoplasm
Which organ are involved in biosynthesis?
nucleus - stores info for construction (DNA)
ER - ribosomes attach, translate RNA -> proteins
Golgi apparatus - modifies & packages synthesised molecules for delivery to where they are needed
Vesicles - delivery containers between organelles
What is energy conversion? Where does it occur?
Fuel molecules (lipids/sugars) -> ATP
initial processing -> cytosol
MAIN PROCESSING -> mitochondria -> ATP -> cytoplasm for use where needed
Breakdown of food/organelles occurs where?
lysosomes (vesicles with hydrolytic enzymes at low pH)
System involved with synthesis & packing of enzymes?
endomembrane system
Importing & exporting molecules occurs how…?
Via cell membrane & associated proteins
- invagination or evagination of cell membrane
- binding to specific transport proteins
- passive transport via channels
T or F - All functional cells engage in reproduction.
False - most do but some do not eg. red blood cells
Which structures pull chromosomes to opposite sides of dividing cells?
microfilaments
Atomic number & atomic weight of an element?
atomic number = no. of protons
atomic weight = no. of protons + no. of neutrons
T or F - electrons have a key role in bond formation & energy transfer
true
What kinds of bonds do electrons enable?
ionic (electrons transferred)
covalent (electrons shared) - strongest bond
- polar covalent
- nonpolar covalent
Least & most number of covalent bonds in element…?
least (1) - hydrogen H
most (5) - phosphorus P
Hydrogen bonds…?
usually occur between H & O or H & N
occur among water, sugars, protein, DNA molecules
Acids do what?
give up protons in solution
Bases do what?
accept protons
H2CO3 is a what? Why?
buffer cause it soaks up H+ ions as pH decreases & releases H+ions as pH rises
Define specific heat…
amount of heat required to raise 1g of a substance by 1 degree celsius
Define the high heat of vaporisation theory…
energy absorbed when water changes from liquid -> gas
-> evaporates -> draws heat from organism -> cooling it
Define the heat of fusion theory…
H2O gives up heat as it freezes -> 8 x more than when it goes from 1 - 0 degrees
Maximum density of H2O is at…?
4 degrees celsius
Specific functionality comes from which elements?
P, O, N, S
What are functional groups?
atoms other than C or H that give specific properties to molecules eg. polarity
Major functional groups are…?
hydroxyl (-OH); carbonyl (C=O); carboxyl (O-C=O); amino (-NH2); sulfhydryl/thiol (-SH); phosphate (-PO4)
The smaller units of polymers are typically combined with…?
dehydration synthesis (H20 gets released)
Common monosaccharides…?
glucose, fructose, ribose, deoxyribose
Glucose + fructose = ?
sucrose
Structural polysaccharide?
cellulose => chains of glucose molecules but with alternating bond configuration from starch
Structural carbohydrate?
chitin => makes up exoskeleton of arthropods & cell wall of fungi
polymer of glucose with amino side chain
Characteristics of lipids…?
mainly C & H hydrophobic energy storage (fats/oils) water-proofing (waxes) lipid bilayer hormones (steroids)
Define the heat of fusion theory…
H2O gives up heat as it freezes -> 8 x more than when it goes from 1 - 0 degrees
Maximum density of H2O is at…?
4 degrees celsius
Specific functionality comes from which elements?
P, O, N, S
What are functional groups?
atoms other than C or H that give specific properties to molecules eg. polarity
Major functional groups are…?
hydroxyl (-OH); carbonyl (C=O); carboxyl (O-C=O); amino (-NH2); sulfhydryl/thiol (-SH); phosphate (-PO4)
The smaller units of polymers are typically combined with…?
dehydration synthesis (H20 gets released)
Common monosaccharides…?
glucose, fructose, ribose, deoxyribose
Name a sulfur-containing functional group
cysteine
Structural polysaccharide?
cellulose => chains of glucose molecules but with alternating bond configuration from starch
Nucleotides serve which other roles?
energy carriers (ATP) electron carriers (NAD+, FAD, NADP+)
Characteristics of lipids…?
mainly C & H hydrophobic energy storage (fats/oils) water-proofing (waxes) lipid bilayer hormones (steroids)
T or F - Oils, fats & waxes may posses carbon rings
false - they contain only C,H & O, have 1 or more FA side chains, and only have linear chains of atoms (NO RINGS)
Phospholipids contain…?
- Polar head (functional group & phosphate group)
- glycerol backbone
- fatty acid (FA) tails
Steroids are…?
lipids containing 4 fused rings & are mainly hormones eg. cholesterol, oestrogen, testosterone
Amino acids contain…?
amino group
variable group
carboxylic acid group
hydrogen
Amino acids join together to form proteins with which bond?
peptide bonds
Name 2 hydrophilic functional groups
glutamic acid
aspartic acid
Name 2 hydrophobic functional groups
phenylalanine
leucine
Name a sulfur-containing functional group
cysteine
Polymers of nucleotides are called…?
nucleic acids
Nucleotides serve which other roles?
energy carriers (ATP) electron carriers (NAD+, FAD, NADP+)
Define selectively permeable
a membrane that allows certain molecules to pass thru it by diffusion & occasionally facilitated diffusion
Different forms of passive movement across membranes…?
diffusion/osmosis
facilitated diffusion
Different forms of active movement across membranes…?
active transport
co-transport
membrane manipulations
Membranes are permeable to these molecules…
dissolved gases
small uncharged polar molecules
ethanol
Membranes are not very permeable to these molecules…
polar molecules
charged molecules
macromolecules
Membranes are semi-permeable to these molecules…
water
urea
Define osmosis
movement of water across a differentially permeable membrane
Define isotonic
same concentration
Define hypertonic
greater concentration
Define hypotonic
lesser concentration
Define equilibrium
concentration of diffusing substances in two compartments are equal
Define selectively permeable
a membrane that allows certain molecules to pass thru it by diffusion & occasionally facilitated diffusion
Example of simple diffusion?
O2 thru phospholipid bilayer
Eg’s of facilitated diffusion?
Cl- thru channel proteins
glucose thru carrier proteins
Eg of osmosis?
H2O osmosis thru aquaporins or phospholipid bilayer
2 main features of active transport…?
movement against concentration gradient
requires energy
Where would active transport be used…?
when a cell is fighting a gradient
eg. bringing nutrients into a cell
waste excretion
pumping ions across membrane
2 types of endocytosis…
pinocytosis - fluids
phagocytosis - particles
List the 4 cell connections…
desmosomes
tight junctions
gap junctions
plasmodesmata
What are desmosomes?
cell connection in SI held together by protein filaments
What are tight junctions?
cell connections in urinary bladder sealed together by proteins
What are gap junctions?
cell connections in the liver connecting adjacent cells by channel proteins
What are plasmodesmata?
cell connections in plant roots connected by membrane-lined channels
