Notes Part 3 Flashcards by Mansi Lamba

eukaryotic cells show directional movement with the help of? Give types

Cytoskeleton

1) Microtubules
2) Microfilaments
3) Intermediate filaments

How well did you know this?

Not at all

Perfectly

An elaborate network of FILAMENTOUS, PROTEINACEOUS structure present in cytoplasm

Cytoskeleton

How well did you know this?

Not at all

Perfectly

What is involved in • motility
• support
• maintenance of shape

Cytoskeleton

How well did you know this?

Not at all

Perfectly

What is made up of alpha and beta subunits

Microtubules

How well did you know this?

Not at all

Perfectly

Wrt cytoskeleton types, which one are hollow/solid

Microtubules: hollow
Microfilaments: solid
Intermediate filaments: hollow

Microtubules and intermediate filaments are HOLLOW

How well did you know this?

Not at all

Perfectly

Protofilaments are constituents of? Sub types?

Boundary of Microtubules consists of 13 parallel protofilaments.

Each protofilament consists of alpha and beta tubulin protein.

How well did you know this?

Not at all

Perfectly

Tubulin proteins are required for the assembing of microtubules?

NON TUBULIN potein: Calmodulin (CALcium MODulating proteIN) is required along with Ca²⁺, Mg²⁺ aaaaaaaand GTP

How well did you know this?

Not at all

Perfectly

Colchicine is famous for? whaaaaaaat? why? how?

It dissolves the non-tubulin protein Calmodulin required for assembling microtubules (which make spindle fibres).

How well did you know this?

Not at all

Perfectly

do you know the diameter of microtubules? what about the core?

25 nm diameter

15 nm core

How well did you know this?

Not at all

Perfectly

cytoskeleton and muscle contraction? related or nah?

Microfilament

How well did you know this?

Not at all

Perfectly

Basket around nucleus and scaffold of chromatin. WHAT WITCHCRAFT IS THIS?

Intermediate filament (ACIDIC PROTEIN)

How well did you know this?

Not at all

Perfectly

Intermediate filaments are contractile or non-contractile?

NON-CONTRACTILE, just like microtubules

How well did you know this?

Not at all

Perfectly

Name the only cytoskeleton that has contractile properties. Link with functions.

Micro filament

Majorly made up of globular actin protein, though it also has filamentous myosin Protein as well.

Its Contractile properties help in
~muscle contraction
~provides strength to PM (IT IS SOLID, pun intended)
~cleavage furrow formation
~pseudopodia formation
~cyclosis (seen in higher plants only)

How well did you know this?

Not at all

Perfectly

Which cytoskeleton helps in spindle fibre (hence assists in anaphasic movement of chromosomes), cilia, flagella formation? Give 2 more functions.

Mictrotubules.

1) determines position of future cell plate
2) helps in INTRAcellular transport (is HOLLOW)

How well did you know this?

Not at all

Perfectly

Acidic/Basic : DNA staining dye, Intermediate filaments, and proteins found in nucleoplasm

Acidic proteins : Intermediate filaments and “NUCLEOPLASM CONTAINS IMPORTANT NUCLEAR ENZYMES (DNA and RNA polymerise) AND SOME ACIDIC PROTEINS”

Basic: DNA is stained by basic dyes like acetocarmine/fuelgen

How well did you know this?

Not at all

Perfectly

URICOSOMES are?

ANOTHER NAME FOR PEROXISOOOOMES
PEROXISOMES ARE URICOSOMES AND URICOSOMES ARE PEROXISOMES
Membrane bound structures found in both animals and plants and contain enzymes like:
~catalase
~urate oxidase
~peroxidase
~glycolate oxidase
~D-amino acidoxidase

How well did you know this?

Not at all

Perfectly

Photorespiration

Photorespiration(also known as the oxidative photosynthetic carbon cycle, or C2photosynthesis) refers to a process in plant metabolism where the enzyme RuBisCO oxygenates RuBP, wasting some of the energy produced by photosynthesis.

Mitochondria, chloroplast and peroxisomes are associated with the process

How well did you know this?

Not at all

Perfectly

Name Microbody that takes part in glyoxylate cycle.

Glyoxisomes

How well did you know this?

Not at all

Perfectly

Where in animals are Glyoxisomes found?

Haha trick question

Fats are converted to carbs in process called? Seen where in plants?

Gluconeogenesis, takes place in glyoxisomes

Which Microbody constitutes 98% lipids?

Sphaerosomes. Found in plant cells only

Endosperm of oils seeds contains which Microbody?

Sphaerosomes.

Name enzymes involved in peroxide metabolism.

GLYCOLATE OXIDASE or URATE OXIDASE

Peroxide destroying/decomposing CATALASE

Name unit membrane bound spherical, refractive bodies which take part in storage and synthesis of fats. Where is it abundantly found?

Sphaerosomes.

~found abundantly in ENDOSPERM OF OIL SEEDS

Which Microbody contains hydroltric enzymes and is synthesised in SER?

Sphaerosomes (plant lysosomes)

Which single membrane bound structure (originating from ER) is found in germinating castor seeds, ground nut seed? why?

GLYOXYSOME Contains enzymes for glyoxylate (CHO-COOH) In these germinating fatty seeds, the insoluble lipids must be converted into soluble carbohydases/sugars for the growing tip. (The glyoxylate cycle allows plants and some microorganisms to grow on acetate because the cycle bypasses the decarboxylation steps of the citric acid cycle. ) The glyoxylate enzymes required for this conversion are not present in animals.

Chromosome having centromere at terminal end: TELOCENTRIC or ACROCENTRIC?

Telocentric. ~The prefixes (tel- and telo-) mean end, terminus, extremity, or completion. They are derived from the Greek (telos) meaning an end or goal. Whereas, The word acro is derived from the Greek word akros which means topmost or highest, also akin to Latin word acer, which means sharp end.

J shaped chromosome is

Acrocentric

Which chromosomes have L and I shape

Sub metacentric and Telocentric

Give the 5 pairs of Trabant chromosomes in humans.

13, 14, 15, 21, 22

Other names for Trabant chromosome?

SAT/Marker chromosome.

What is the use of SC (I)? What takes over its functioning in its absence?

Some chromosomes may have additional constrictions termed as non staining secondary constrictions or NOR (nuclear organiser) near their ends. The part of the chromosome beyond the secondary constriction is called satellite. SC(I) is metabolically active and functions as a NO (nucleolar organiser) by giving rise to the nucleoli during the interphase hence aka Nucleolus organising region. ("SAT chromosomes [produce nucleoli for ribosome synthesis"). Primary constriction/Centromere take over its functioning in the absence of SC (I).

which constrictions stainable?

Trick question. None. They're all non-stainable.

Sub-metacentric chromosomes are ISOBRACHIAL. True/False.

False. Sub-metacentric chromosomes are HETEROBRACHIAL. Metacentric chromosomes are ISOBRACHIAL.

Centromeric index, huh?

Ratio of chromosomal arms.

Features of a chromosome by which a diploid set of chromosomes of a diploid organism can be identified.

KAAAARYOTYPE ``` Includes (6) ~number of chromosomes ~relative size ~position of centromere ~length of arms ~secondary constriction ~satellite ``` (May be symmetrical or asymmetrical)

In which cell was the nucleus discovered?

Orchid root cell.

Euchromatin replicates early/late in S-phase?

Eaaaarly

Best definition for chromatin (wrt to a certain phase in cell cycle, what about in other states?)

Loose indistinct network of nucleoprotein fibres found in the interphase nucleus. However, In different stages of cell division, cell shows structured chromosomes in place of chromatin.

Chromosome discovered in? by?

Pollen mother cell of Tradescantia. HOFMEISTER (he called it the nuclear filament)

Give comparison of chromosomes: plant/animal cells and Monocot/Dicot

Plants have longer chromosomes than animals. | Monocots have longer chromosomes than dicots.

IDIOGRAM

Diagram of karyotype of a species | karyotype is the number and appearance of the chromosomes in a cell

TRIVIA TIME: name the smallest and largest enzyme

smallest: peroxisome largest: catalase

what does catalase exaaaaactly do?

it is an antioxidant enzyme which catalyses the breakdown/decomposition of peroxide into water and oxygen. It is found in nearly all organisms exposed to oxygen and is extremely essential since it counters the harmful side-effects of oxygen metabolism (protects against the free radicals formed when we break down food or those formed via exposure to radiation/pollution.)

which cytoskeleton is responsible for cyclosis seen in higher plants? (why not in bacteria?)

microfilaments are responsible for cyclosis. | cytoskeleton: present in eukaryotes only