Summary - A level Biology

ME DELL


Y
Proteins-Keratin
all living things comprised
-


are

Of cells ↑ desmin
arise pre-existing
intermediate filaments
-cells only from
maintains cell shape
+ anchors
Cells
nucleus and some other
carry genetic info
cells organelles
by DNA
-

+
motor proteins :

Passed from parent to daughter actin filaments :




-
divide animal Kensin and dynein
muscle contraction cells ;

microtubles : more



i
& chromosomes
Cell division ;
during
I' formation of cellplate
provide tracks :
for
intracellular Microvilli and Cilia
transport cell
membrane enclosed nucleus mobility
(made of




A
C microtubles)




O
↓
hollow tubes
centriese
of tublin
L proteins
lysosome ant
digestive organelle found Cells
&
S
-
in most animal

digesting and
cells

waste
-
release Spindle
Fibres during CD
=
S
-
-




processing


Peroxisomes
-contain
- hydrogen peroxide
-break down
fatty
E
via acid chains
ribosomes
B-oxidation
read' DNA molecules to make

proteins golgi apparatus
not considered ·
organelles
-


-protein and vesicle
because no membrane sorting centre
-proteins are
-
made up of RNA and proteins tagged
t resicles go
Off Golgi apparatus
FOUND IN
...

LEXOCTOSIS)




&n
I.
free in cytoplasm




...
2
. :
rough ER &




⑧ · a :
3 Mitochondrion t
⑧
chloroplasts
.




· endoplasmic reticulum
O
· Os




g g8 .
1
↑
↑ 0
.
8 rough ER : has ribosomes attached that
allows protein modifications + directs
transportation out cell ; has
chaperone
Proteins to help protein folding
2 Smooth ER
.
:
lacks ribosomes ; involved in
lipid + carbs
synthesis hormone production
nuclear ,
,
and
nucleus membrane detoxification
↓ -
double membrane
nucleolus




O
Chromos
Omes-RNA -selective
↓ Synthesis
Outer
member and
- DNA
genes-DNA coding
histones regionsers
organisin
=



↓

intermembrane
e




E
SA




&
Cristal




/

%
-I
more folds




2
mitochondrion


"
· - increase the
⑧



&
SA for Chemical -semi-autonomous ; some of their own

reactions genes




↑
+
replication by binary fission
~
⑳




*
thought
-



to have evolved
& by an
anaerobic
Na prokaryote engulfing an
aerobic
prokaryote
+
neoryl
(endosymbiotic

, N T
Simple epithelial : one layer of cells


I .
epithelial : cover the body and line its cavities stratified epithelia :
multiple layers
↑
↓ ↓
protection from pathogen absorption ,
Secretion,
invasion and sensation Pseudo stratified epithelia : One layer ,




basement membrane although appear multiple
: connective tissue
, underlying layer cuboidal : cube-shaped cells
to which epithelial cells are joined

2 . connective :
supports body , provides framework
- Columnar :
long and thin cells


-
contribute mainly to the stroma (support Structure
↓ squamous : flat and scalelike
most cells secrete collagen t elastin to form extracellular Matrix
-




-examples : bone cartilage tendons
,
,
, ligaments

2
. ?? . % % % & a




t DOMAINS :




S
Similar RNA I.
karya
no membrane bound organelles Polymerases 2 .

Archaea : extremophiles
-
lack key organelles such as mitochondria
Photosynthetic t Chemosynthetic
cell used
·
membrane for electron transport chain resistant to many antibiotics
-
primandApgeneratione divide by
budding or binary fission
3 .
bacteria :


Cell membrane + cytoplasm
Some have flagella +
fimbriae




O
&
smaller ribosomes than eukaryotes
ribosome




&




&
⑳
7 flagellum
cell wall




T
-
↑
↑
: determined by Gram staining
Cell membrane ·
I .
Gram positive
envelop absorbs crystal
-




Violet stain -> deep
DNA (nucleoid purple
cell
-



region) wall made of peptidogly can
↳Structural functions +




⑧
Pathogen protection

2 .
Gram negative
hollow made of envel Op Satranin stain
-



absorbs
,
counter




↑
flagellin >
-

pink-red
cell wall has a thinner layer of peptidoglycan
-




has an outer membrane of phospholipids
-


L
Connects
filament and lipopolysaccharides
O
+




body ↳ triggers immune response in



-
humans

When the basal body rotates it

exerts torque on the filament
which spins and propels bacterium




CLASSIFICATIONS :



Cocci Spherical bacteria
-
:



SHAP E >
- bacilli :
rod-shaped bacteria
- Spirilli :
Spiral-shaped bacteria

Obligate acrobes :
Of required for metabolism

anaerobes : does not require O2 (exfermentation

, i
feature prokaryotic eukaryotic
nucleus not present
present

DNA circular linear

DNA organisation proteins fold and condense DNA associated with proteins called histones

extra chromosoma A circular DNA called plasmids Only present in certain organelles such as



Chloroplasts and mitochondria

organelles non membrane-bound both membrane-boun & and non membrane-bound

cell wall Peptidoglycan Chitin in fungi ,
cellulose in plants , not present in animals

ribosomes smaller ,
70s larger ,
80s


Cytoskeleton present present , m o re complex


reproduction binary fission a sexual or sexual


cell unicellular unicellular and multicellular
type

cell-surface membrane present present




IBI COILCO I AIL ERIMENT



on
-
. . . - >r




Calcium ions = nerve impulse transmission ,
muscle contraction
Ca2 +



Sodiumions-nerve
impulse transmission , Kidney function n




transmission
potassiumions
: nerve impulse , stomatal opening o




hydrogen ions = Catalysis of reactions
, pH deter mination
+
H




ammonium ions -
production of nitrate ions by bac teria
NH +
+




Unionis
-
-
........ 111111111>111111




nitrate ions nitrogen supply to plants for amino acid and protein formation

NO3-

ions blood o
hydrogencarbonate
:
maintenance of a




Chloride ions-balance positive charge of Na and Kions in cells

CL-


Phosphate ions-cell membrane formation ,
nucleic acid and ATP formation , bone formation

P043-

hydroxide ions = Calalysis of reactions , pH determination
OH-




carbon

hydrogen
Carbon
hydrogen
↑
carbon


carbohydrates
↑
Lipids
hydrogen ↑
proteins
↑
-

Carbon
↑ ndrogena
↳ c (20
nitrogen
↓ ↓ ↓ ↓
Sulfur Phosphorus
Oxy gen
hydrogen Oxygen nitrogen