Secara ilmiah dapat
dinyatakan ada sel yang mati
(nekrosis atau apoptosis) dan
sel yang hidup (normal atau
tumor/kanker) berberdasarkan
gejala/fenomena - nya.
Sebutkan 3 gejala sel yang
hidup dan
jelaskan uraian keterkaitannya
dengan berfungsinya gen
(DNA-RNA)
SETIAP SEL TANAMAN DAN SEL MAMALIA BERSIFAT TOTIPOTEN.
• Dari setiap sel tanaman (dari akar, daun dll) dapat ditumbuhkan (dikulturkan)
menjadi tanaman seutuhnya yang identik,
• Namun dari sel hewan tidak dapat sedemikian,
• Hanya saja dengan penemuan teknologi kloning domba “dolly” yang identik
dengan induknya dapat dibuktikan totipotensi sel hewan (mamalia).
SESUAI DENGAN DIFINISI TOTIPOTEN, JELASKAN BAGAIMANA
TEKNOLOGI KLONING DOMBA DAPAT MEMBUKTIKAN TOTIPOTENSI
SEL HEWAN
1. TOTIPOTENT
2. PLURIPOTENT ??? The inner cell mass cells can form virtually every type
of cell found in the human body, they cannot form an organism.Therefore,
these cells are referred to as pluripotent, that is, they can give rise to many
types of cells but not a whole organism
3. MULTIPOTENT ??? Pluripotent stem cells undergo further specialization
into stem cells that are committed to give rise to cells that have a particular
function. These more specialized stem cells are called multipotent—
capable of giving rise to several kinds of cells, tissues, or structures.
STRUKTUR MEMBRAN PLASMA SEL
DAPAT DIJELASKAN DENGAN
MODEL “FLUID MOZAIC”.
(a)Jelaskan pengertian tersebut, serta
(b)Tunjukkan adanya empat jenis (type) protein sesuai
posisinya pada membran plasma dalam gambar
skematik.
(c) Sebutkan dengan sedikit penjelasan 4 jenis protein
pada membran plasma sesuai fungsinya
(d)Protein yang menghubungan dengan sel tetangganya
atau biomatriks diluar sel, adalah integrine, cadherin,
cam (cell adhesive molecul), coba jelaskan dengan
skematik bedanya
Vincristrin sebagai obat dari tanaman untuk
terapi tumor dengan mekanisme merubah
atau menghambat konformasi (bentuk)
mikrotubuli. Mikrotubulin (dan atau
mikrofilament) berupa struktur gabungan
(polimer) tersusun dari banyak unit protein
monomer
1. Apa fungsi mikrotobuli yang dihambat/
diganggu oleh vincristin.
2. Sebutkan 1 fungsi mikrotobuli yang lain.
1. Phagosome
2. Lysosome
3. Peroxysome
4. Proteasome
Merupakan organela sel dengan fungsi
mencernakan materi yang tidak diperlukan
oleh sel atau diproses selanjutnya.
Diantara 4 “some” tersebut ada perbedaan
pembentukan dan fungsinya, jelaskan !
Lysosomes are the cells' garbage disposal system. They degrade the
products of injestion, such as the bacterium that has been taken in by
phagocytosis
Lysosomes also degrade worn out organelles such as mitochondria.
A third function for lysosomes is to handle the products of receptormediated endocytosis such as the receptor, ligand and associated
membrane
Peroxisomes are organelles that contain oxidative enzymes,
They are self replicating, like the mitochondria.
Bakteri patogen yang
dikenal asing oleh
“macrophage” kemudian di
proses untuk akhirnya
gugus antigen bakteri
dipresentasikan di luar
selnya sehingga proses
respon imun dapat
berlanjut ( ke limfosit-T)
Sebutkan dan jelaskan dua
proses biologik yang terjadi
dengan menyebutkan
berbagai organela sel yang
terlibat
B
A
Limfosit-T membunuh sel tumor dengan cara
berbeda dari Macrophage
Sebutkan dan jelaskan dua proses biologis beserta
organela sel dan molekul yang terlibat dalam proses
sehingga sampai sel tumor dapat mati
KADAR LDL (KOLESTEROL) DALAM DARAH
YANG TINGGI BOLEH JADI DISEBABKAN ADA
GANGGUAN PADA PROSES BIOLOGIS
“RECEPTOR MEDIATED ENDOCYTOSIS”
1. JELASKAN PEMIKIRAN TERSEBUT
2. JELASKAN PULA PEMIKIRAN IDENTIK
TERSEBUT YANG TERJADI PADA VIRUS
EKSOSITOSIS -> SEKRESI
ENDOSITOSIS
RECEPTOR
MEDIATED
ENDOSITOSIS
- HORMON AND GROWTH FACTOR
- SERUM TRANSPORT PROTEIN
( LDL = Low Density Lipoprotein )
- ANTIBODY
- VIRUS
- TOKXINS AND LECTINS
PALING SEDIKIT ADA DUA PROSES
BIOLOGIS PENTING SEHINGGA
DAPAT DIJELASKAN BAGAIMANA
SPERMA DAPAT MENEMBUS
LAPISAN OVUM SEBELUM
TERJADI FERTILISASI
JELASKAN !
Sel tumor/kanker pada stadium lanjut dapat
berpindah dan tumbuh (metastase) di
tempat lain dalam tubuh manusia pada hal
sel tsb. Tidak mempunyai alat bantu gerak
(ekor atau rambut gerak)
1. Jelaskan proses/gejala biologis apa
sehingga sel kanker dapat
berpindah/bergerak
2. Jelaskan proses/gelaja biologis apa
sehingga sel kanker hanya dapat metastase
pada organ atau jaringan tertentu.
RIBOSOME SEBAGAI ORGANELA SEL TEMPAT DIMANA
PROTEIN/PEPTIDA DIBUAT/DIBIOSINTESIS
1. APA FUNGSI SUSUNAN “POLYRIBOSOME”, JELASKAN !
2. KLORAMFENIKOL SEBAGAI ANTIBIOTIKA MEMBUNUH BAKTERI
DENGAN CARA MENGHAMBAT BIOSINTESIS PROTEIN, NAMUN
BIOSINTESIS PROTEIN MANUSIA (PASIEN) TIDAK DIHAMBAT),
JELASKAN FENOMENA TERSEBUT.
Prokaryotic Ribosomes
Eukaryotic Ribosomes
Suatu protein yang berada&berfungsi di
membran plasma ( cell membrane) berasal dari
pembuatan (di-biosintesis) di ribosom. (Protein
biosintesis and their transport to the position)
(a)Jelaskan perjalanan ( tahapan proses biologis
dan beberapa organel sel lain yang berperan)
protein tersebut dari ribosom ke membran
plasma, demikian pula
(b)bagaimana penjelasannya bahwa suatu protein
posisi nya di membran plasma dan tidak di
tempat/posisi yang lain
Nekrosis ???  Apoptosis
Cell death occurs by 2 processes Necrosis and Apoptosis.
Unprogrammed cell death, Necrosis, leads to the bursting of a cell and
its contents being spilled into the extracellular space, followed by
inflammation.
Programmed cell death, or Apoptosis (a term first coined in 1972), is a
series of regulated steps modification of cell membrane, DNA
condensation and severing, cytoskeleton dissassembly, followed by
"blebbing" cytoplasmic and nuclear contents into membrane bound
fragments, engulfed by macrophages (phagocytosis).
Cell Death is a field of research that has grown enormously in recent
years. The growing interest is not only for its biological relevance in
maintaining homeostasis in multicellular organisms, but also for its
potential clinical application in regulating cell numbers (both up and
down). The key concepts are:
cell cycle, mitosis, meiosis, apoptosis, necrosis, signaling pathways, cell
organelles, mitochondria, cytoskeleton, microtubules, microfilament, Bcl
2, P53, caspase, DNA ladder, death receptor, growth factors, Akt,
cytochrome-c.
The breast is one of the few organs that completes its development after birth in two
discrete physiological states: puberty and pregnancy. During these stages there are
noticeable alterations in breast proliferation and differentiation. Changes in the apoptotic
regulatory proteins of the Bcl-2 family occur in part due to the influence of oestrogens
and progesterone. Cells in the termini of the developing mammary ducts remain
mitotically quiescent until the onset of pregnancy. Then rapid epithelial proliferation
occurs, with additional ductal branching and lobuloalveolar growth.
After lactation there is massive restructuring and apoptosis leading to involution and a
return to the primary structure. In the absence of pregnancy there is repeated cycling of
the resting state in parallel with menstruation until there follows a gradual process of
senile involution with menopause. Most apoptotic changes occur in the lobular unit of the
terminal duct, with cyclical changes through the menstrual cycle and a peak of apoptosis
close to the end of the menstrual cycle. A peak of proliferation occurs a few days earlier.
It is clear that a balance between proliferation, differentiation, and death of the cells
throughout the mammary gland is critical for normal development and homoeostasis.
Situations that can upregulate cell proliferation or downregulate apoptosis may allow
accumulation of mutations that result in breast cancer. Defects in the cellular processes
that detect substantive damage to DNA and lead to the deletion of the cells can lead to
the initial acquisition of these cancer related mutations.
Cell Death and Its Regulation
In the preceding sections, we have described various extracellular signaling molecules,
and their intracellular signaling pathways, that play a role in regulating cell division,
pattern formation, differentiation, morphogenesis, and motility. In this final section, we
consider signaling pathways regulating cell survival. Programmed cell death, a central
mechanism controlling multicellular development, leads to deletion of entire structures
(e.g., the tail in developing human embryos), sculpts specific tissues by ablating fields of
cells (e.g., tissue between developing digits), and regulates the number of neurons in the
nervous system. In the mammalian nervous system, for instance, the majority of cells
generated during development also die during development.
Cellular interactions regulate cell death in two fundamentally different ways.
Most, if not all, cells in multicellular organisms require signals to stay alive. In the
absence of such survival signals, frequently referred to as trophic factors, cells activate a
"suicide" program. In some developmental contexts, including the immune system,
specific signals induce a "murder" program that kills cells. Whether cells commit suicide
for lack of survival signals or are murdered by killing signals from other cells, recent
studies suggest that death is mediated by a common molecular pathway. In this final
section, we first distinguish programmed cell death from death due to tissue injury, then
consider the role of trophic factors in neuronal development, and finally describe the
evolutionarily conserved effector pathway that leads to cell suicide or murder.
In the absence of such survival signals,
frequently referred to as trophic factors,
cells activate a "suicide" program.