NON MEMBRANOUS CYTOSKELETON

the cytoskeleton gives what to the cell

the shape

a type of cytoskeleton

• microtubules

what are microtubules?

• hollow tubules

• made of protofilaments (polymer of tubulin)

function of microtubules

how do microtubules grow

from the microtubule organizing center (mtoc)

how does the movement of organelles happen?

molecular motor proteins (there are 2)

what are the 2 molecular proteins

• dyenin

• kinesins

dyenin molecular protein

organelles move from

CELL PERPIHERY ———> MTOC

kinesins molecular protein

organelles move from

• MTOC ——→ CELL PERIPHERY

microfilaments

• SOLID tubes

• actin & myosin

• ankyrin & specimen in RBC

• dystrophin in muscle cells

microfilaments is in charge of what?

contractility of protoplasm

there are 4 major classes in intermediate filaments

1. keratins

2. vimentins

3. neurofilaments

4. lamins

keratins is

• skin

• hair

vimentins

are mesoderm derived cells

neurofilaments

found in neurons

lamins

found in nuclear envelope

inclusions

that have non living things inside cells

• glycogen

• lipids

• crystalline inclusions

inclusions contain

glycogen that stores sugar

• found in muscles and in the liver

glycogen in the inclusion contain

• b particles (tiny and single)

• a cluster particles (group of glycogen)

lipids will be

spherical droplets of neutral lipids

the lipids in the inclusions can be

histologically prepared (using dyes to stain) - lipids will be removed

what type of dyes are used to remove lipids in the inclusions

• glutaraldehyde

• osmium tetroxide

the dyes will make the lipids what color?

dark

crystalline inclusions are specifically found in

• sertoli cells

• interstitial cells of leydig

inclusions also create?

pigments

what pigements?

• lipofuscin

• hemosiderin

• melanin

lipofuscin will result in what pigement?

brown-gold

the lipofuscin pigement have what length of life

long life

ex: cardiac, brain cells, skeletal

hemosiderin will result in what pigment?

brown

• outcome of hemoglobin degradation

• iron storage pigment

melanin results in

skin color and hair color (melanosomes)

cytoplasmic matrix (cytosol)

• ground substance or cytosol

cytoplasmic matrix is an

aqueous gel

cytoplasmic matrix has

• molecules of different shape and size

the cytoplasmic matrix is the “ .”

largest single component in most cells

the cytoplasmic is the site of what?

protein synthesis

is a network of what kind? (cytoplasmic matrix)

3D network of microtrabecular strands & cross linkers

the nucleus

• largest organelle

nucleus will stain

• purple

• blue (H&E)

when the nucleus is magnified you will see clumps what are those clumps

chromatin (contain genetic material)

nuclear envelope

has a double membrane with pores (communicate btwn the nucleus & cytoplasm)

• pertibular cisernae

• will break during cell division and then form after division is complete

chromatin consists of

• ribonucleoproteins

• histones

chromatin is separated into two kinds

1. condensed

2. dispersed

condensed chromatin is known as

heterochromatin - sustainable

dispersed chromatin is known as

euchromatin - not stainable

when dividing ______ become ____ and are _____

chromsomes, visible, basophilic

human cells are

diploid 2n

germ cells are

haploid n

polyploidy is

abnormal amount of cells that have more than usual amount of chromosomes

nucleolus

• in the nucleus

• retractile

• eccentric

• basophilic

  • rna gets formed

cell division (MITOSIS) occurs in

somatic cells

prophase

• spindle forms

• sister chromatids migrate toward center of spindle

metaphase

• centromeres align to spindle

• chromatids attach to different poles

anaphase

• chromsomes migrate toward poles

• chromatids separate

• cytokinesis begins

telophase

• nuclear membrane reappears

meiosis occurs only in

germ cells

meiosis occurs in

eukaryotes

humans have

• 46 (total) or 23 pairs of chromosomes

  • 23 are sperm

  • 23 are ova

prophase i

exteneded into differnt phases (5)

what are the 5 phases of prophase 1

1. Leptotene

2. Zygotene

3. Pachytene

4. Diplotene

5. Diakinesis

leptotene

chromosomes condese, sister chromatids visible

zygotene

synapsis and tetrad formed

pachytene

chromatids continue to condense

diakinesis

complete condensation

diplotene

separation of paired chromosomes

metaphase i

spindle develops chromosomes align at plate

anaphase i

sister chromatids separatet

telophase i

division complete and homologous chromatids separate

interphase

small recess

cell locomotion

cells have the ability to move

• ambeoid movement of leukocytes

cell movement can be

• random

• directional

directional movement is called

chemotaxis

necrosis

cell death due to injury or toxins (we dont have control over it)

aptosis

active or programmed cell death

• life span if a few days-80 years