Topic 1 Flashcards
(97 cards)
1
Q
Cell structure and function
A
- come from pre-existing life
- communicate w other cells
- bounded by a membrane
-maintain an internal environment
2
Q
Factors of Life
A
-common set of elements
-made of cells
-contain genetic info
-grow and change
-respond to the environment
-use and make molecules
-extract and use energy
- exist and evolve
3
Q
Viruses pros
A
-contain nucleic acids
-can replicate
-evolve and adapt to environment
4
Q
Virus cons
A
- x individually replicate
- x comprised of cells
- x extract energy
- x contain metabolic reactions to be considered alive
5
Q
Cell theory
A
- fundamental unit of life
- all organisms are composed of cells
- all cells come from pre-existing cells
- modern cells evolved from a common ancestor
6
Q
2 theories of life forming on earth
A
- Miller-Urey experiments
- Alien life - the Murchinson meteriorite
7
Q
what are stromolites
A
layers of limestone that contain layers of fossilised cyanobacteria that can be traced back 5-7 billion years ago
hence they provide evidence for the beginning of life on earth
8
Q
properties of water
A
-hydrogen bonding -> high specific heat capacity
- high melting and boiling point
-high heat of vaporisation
- cohesion (H bonding bw H2O molecules
-adhesion (H bonding of H2O and other molecules)
9
Q
chemical reactions of water
A
weak acid
H2O + H+ —> H3O+
weak base
H2O + OH- —> 2OH-
10
Q
3 intermolecular forces
A
- dipole-dipole
- hydrogen
- dispersion
11
Q
dipole-dipole
A
attraction bw oppositely charged poles of two different molecules
hydrophillic
12
Q
hydrogen bonding
A
hydrogen bonded to a hydrogen or NOF
13
Q
dispersion
A
= any force bw non-polar molecules
hydrophobic
14
Q
macromolecules
A
biological polymers composed of a long chain of repeating monomers
15
Q
condensation
A
OH- groups react with H+ to form a covalent bond, losing H2O in the process
16
Q
hydrolysis
A
enzyme assisted reaction where H2O is added to a molecule to break covalent bonds and split it
17
Q
carbohydrates
A
(CH2O)n
source of chemical energy
form structural components
18
Q
monosaccharides
A
3 C sugar = glyceraldehyde
4C sugar = ribose, deoxyribose
6C sugar = fructose, glucose
19
Q
disaccharides
A
maltose = glucose + glucose
lactose = glucose + galactose
sucrose = glucose + fructose
20
Q
polysaccharides
A
glycogen
cellulose
starch
21
Q
glycogen
A
primary store of energy in animals
glucose polymer
1-4 and 1-6 glycosidic bonds
22
Q
cellulose
A
linear polysaccharide of glucose in plants
structure of plant cell wall
23
Q
starch
A
primary energy store in plants
branched molecules
24
Q
nucleic acids
A
RNA
DNA
25
RNA
ribose sugar
single stranded
A U C G
26
DNA
deoxyribose sugar
double stranded
A T C G
27
purines
A
G
28
pyrimadines
C
U
T
29
non-polar R groups
hydrophobic
can form dispersion forces
30
polar R groups
hydrophillic
can form ionic interactions
31
polar uncharged R groups
hydrophillic
H bonds and dipole-dipole interactions
32
primary structure
amino acid monomers joined in peptide chains
33
secondary structure
polypeptide chains may form alpha helices and beta pleated sheets
34
tertiary structure
polypeptides fold to form specific shapes
35
quaternary structure
two or more polypeptide chains assemble to form larger protein molecules
36
what causes proteins to denature
high temp, high or low pH, high conc of polar molecules, non-polar substances via hydrophobic interactions
37
what does protein denaturation effect
secondary and tertiary structure
38
lipids
insoluble in water
non-polar
held together by dispersion forces
composed of C H O
dissolve readily in organic solvent
smaller proportion of oxygen compared to carbohydrates
39
how does pH cause denaturation
1. addition or removal of H+ ions
2. changes COOH and NH2 containing R groups
3. disrupts ionic reactions
40
how does high temp cause denaturation
1. energy disrupts intermolecular interactions in R groups
41
how does addition of polar cause denaturation
1. disrupts polar R groups
2. disrupts dipole-dipole and H bonds
42
how does addition of non-polar cause dentauration
1. disrupts all non-polar R groups
2.interferes with dispersion forces
43
3 domains of life
bacteria
archaea
eukaryotes
44
archaea v bacteria
transcription and translation in archaea are more similar to euk than bacteria
archaea lipids joined by an ether bond and lack a peptidoglycan wall
archaea not found to produce resting spores
45
Structures in prokaryotes
ribosomes
cytoplasm
nucleoid
nucleus
mitachondria
chloroplast
46
ribosomes
made of rRNA and proteins
site of protein synthesis
47
cytoplasm
rest of cells content
cell membrane, cell wall, pilli, flagellum, capsule
48
nucleoid
where DNA is located
49
gram positive
stains purple
simple cell wall
single layer thick cell wall
peptidoglycan layer thick
no outer membrane
low lipid levels
susceptible to antibiotics
less toxic
50
gram negative
does not stain
structurally complex cell wall
double-layered thin cell wall
thin, single peptidoglycan layer
outer membrane
20-30% lipids
very resistant to antibiotics
usually more toxic
51
nucleus
double layered membrane
presence of nuclear pores
nucleolus = subregion of nucleus containing ribosomes genes
contains DNA in long strands coiled with histone proteins (chromosomes)
52
mitochondria
carry out aerobic respiration in euk cells
53
chloroplasts
site of photosynthesis
54
origins of mitachondria
primary endosymbiosis of purple bacteria
55
origins of nucleus
invagination of the plasma membrane around the nucleolus of an ancient prokaryote
56
origins of chloroplast
primary endosymbiosis of a photosynthetic cyanobacteria
57
primary endosymbiosis
plasma w 2 membrans
58
secondary endosymbiosis
plasma w 4 membranes
59
evidence for endosymbiosis
appear morphologically similar
surrounded by an outer membrane
semi-autonomous
contain ribosomes
metabolism is similar to prokaryotes
60
cytosol
site of biochemical processes
space bw organelles
61
cytoskeleton
composed of protein
microtubule, microfilament and intermediate filament
structural elements of cytoplasm
organises cellular activities and structures
62
microtubules
hollow tubes
25 nm and 15 nm lumen
maintain cell shape, organelle movement
63
microfilaments
2 intertwined strands of actin
maintains cell shape, changes in cell shape, muscle contraction, cytoplasmic streaming, cell division (cleavage furrow)
64
intermediate filaments
fibrous proteins supercoiled into thicker cables (keratin)
8-12 nm
maintain cell shape, anchorage of nucleus, contain the organelles, form nuclear lamina
65
secretory system componants
endoplasmic reticulum
golgi body
plant vacuoles
lysosomes
microbodies
66
endoplasmic reticulum
produces proteins and lipids
membrane CISTERNAE
67
golgi body
collection, packaging and distribution of molecules
68
plant vacuoles
contain hydrolytic enymes
stores nutrients and pigments and maintains cell turgor pressure
69
lysosomes
breakdown materials
acidic interior
70
microbodies
contain enzymes derived from free ribosomes in cytoplasms
perioxomes breakdown AA
glycosomes break down fatty acids
71
diffusion
high concentration to a low concentration
72
osmosis
diffusion of water across a selectively permeable membrane
73
facilitated diffusion
transport proteins allow transport of hydrophilic substances
aquaporins allow for H2O passage
carrier proteins bind to molecules and change shape
74
active transport
against concentration gradient
rate affected by availability of carrier proteins, substrates and ATP
75
2 types of endocytosis
pinocytosis
phagocytosis
76
pinocytosis
bring fluids and small molecules into the cell
factors = stimulus and mechanism
77
phagocytosis
brings in solid partixles
factors = presence of pathogens and cellular debris
78
DNA replication fork
DNA helicase attaches and unwinds DNA
SSB bind to single-stranded DNA to prevent rewinding
79
lagging strand synthesis
polymerase moves 5'-3' on leading strand
lagging strand DNA primase attaches RNA primer
DNA polymerase b/w primers form okazaki fragments
80
replication in prokaryotes
initiator protein binds to ORC and initiates DNA separation
DNA helicase binds to unwind DNA which creates a replication bubble
DNA polymerase synthesises new strands as 2 forks meet at termination site.
81
replication in eukaryotes
multiple origins of replication initiated by ORC
DNA helicase unwinds the DNA to create a replication bubble
RNA primers allow DNA polymerase to move along the leading and lagging strands
last RNA primer removed
gDNA overhang left
telomerase extends overhanging non-coding DNA
replication concludes when replication bubbles meet
82
prokaryotic cell cycle
DNA-A-ATP binds to Oric region which causes separation
DNA-A-ATP converted to DNA-A-ADP
polymerase releases energy
chromosome replication begins at origin
replication continues
replication finished
plasma membrane pinched inwards by tubulin as new cell wall forms 2 seperate cells
83
G1 phase
metabolic activity and growth
84
G2 phase
metabolic activity and growth preparation for division
85
s phase
metabolic activity, growth and DNA replication
86
mitosis
distribution of chromosomes between 2 daughter nuclei
87
cytokenesis
division of cytoplasm producing 2 daughter cells
88
4 phases of mitosis
prophase
prometaphase
metaphase
anaphase
telophase
89
anaphase
paired sister chromatids separate
daughter chromosomes move to opposite poles of the cell
89
prometaphase
nuclear membrane envelope breaks down
kinetochore microtubule appear
89
prophase
chromosomes condense
centrosomes move to opposite poles of cell
89
cytokinesis plant cell
row of vesicles form the cell plate
89
metaphase
centromeres become alined on cell equator
90
telophase
daughter chromosomes reach poles
nuclear envelopes reform
90
90
cytokinesis animal
separated cyotplasms
contractive ring
membrane
91
