Cells Flashcards
(35 cards)
1
Q
What is Cell Theory?
A
- cell is the smallest unit to retain life properties
- all organism are made up of 1+ cells
- new cells arise via division of old cells
2
Q
Electron microscope vs Light microscope
A
- e-, magnets to focus, high res, high mag. complex sample preparation
- light, low res, low mag, living cells, show cell and interior
3
Q
SEM vs TEM
A
SEM: cell SURFACE
TEM: cell internals
4
Q
Prokaryote
A
single celled, no membrane bound organelles
5
Q
Cell wall (plant)
A
- made of cellulose, hemicellulose and pectin
- shape, communication, defense
6
Q
Cell wall (bacteria)
A
- made of peptidoglycan
- shape, distinction, target for antibiotics
7
Q
Cell membrane
A
- phospholipid bilayer, marker, channel and receptor proteins
- structure, transport of molecules, recognises and responds to chemical signals
8
Q
What molecules are permeable and impermeable to phospholipid bilayers?
A
- yes: water, small uncharged
- no: charged, hydrophilic, marcomolecules
9
Q
Passive diffusion
A
- high to low
- no energy/ passive
10
Q
Facilitated diffusion
A
- high to low
- gated channels allow molecules to move in and out after activation
11
Q
What can activate gated channels (4)
A
- ligands e.g. hormones
- voltage e.g. nerves
- light
- mechanical triggers e.g. cilia
12
Q
Active transport
A
- low to high
- active (energy)
- carrier proteins and membrane bound vesicles
13
Q
Paracrine signalling
A
- local
- chemokines and interleukins
14
Q
Synaptic signalling
A
- local
- neurotransmitters e.g. acetylcholine
15
Q
Endocrine signalling
A
- long distance
- proteins, steroids, peptides, modified amino acids
16
Q
Cytoplasm
A
- semi-fluid held within boundary of cell membrane
- holds the cytoskeleton
17
Q
Nucleus
A
- nuclear membrane: transport in/out
- nucleolus: where genes are transcribed
- nucleoplasm: equivalent of cytoplasm
18
Q
Smooth endoplasmic reticulum
A
- synthesises lipids
- no ribosomes
19
Q
Rough endoplasmic reticulum
A
- synthesises proteins
- ribosomes
20
Q
Ribosomes
A
- synthesises proteins
21
Q
Ribosome size in prokaryotes
A
50s larger unit, 30s smaller unit
22
Q
Ribosome size in eukaryotes
A
60s larger unit, 40s smaller unit
23
Q
Ribosome size in mitochondria
A
39s n larger unit, 28s in smaller unit
24
Q
Golgi
A
- processes and packages proteins
- makes lysosomes
25
Cellular respiration in animals
- glycolysis: glucose into pyruvate in cytoplasm
- citric acid cycle: oxidation of pyruvate into CO2 and H2O and energy as ATP in mitochondria
26
Cellular respiration in plants
- chlorophyll in chloroplasts traps energy from light for photosynthesis
27
Mitochondria
- outer membrane: transport in/out
- inner membrane: catalyses cellular respiration
28
Chloroplast
- thylakoids contain chlorophyll
- chlorophyll do the photosynthesis :)
29
Origins of mitochondria and chloroplasts
- Mitochondria evolved from aerobic bacteria
- Chloroplasts evolved from cyanobacteria
30
Evidence towards mitochondria/chloroplast evolution
- circular DNA
- mtDNA/cpDNA encodes proteins for the organelle only
- genes transcribed as a single molecule
- structure resembles bacteria more than eukaryotic cells
31
Cytoskeleton
- proteins in cytoplasm
- cell shape, organisation of internal structures
- movement within cell
32
Cytoskeleton consistuents
- Microfilaments
- intermediate filaments
- microtubules
33
Cytoskeleton microfilaments
- Actin protein
- cell division, cell motility
34
Cytoskeleton intermediate filaments
- keratin protein
- anchorage of organelles
35
Cytoskeleton microtubules
- a-tubulin and b-tubulin protein
- cell motility, spindle formation
