the cell Flashcards
The study of cellular structures of the body
histology
observation: the key to identifying cell types
how many cells do we have in our body
10^14 or 100trillion cells
200+ cell types
who discovered cell
Robert Hooke
- coined the term cell
-cork under microscope
Anton Van Leeuwenhoek
Observed living cell (microorganism and protozoa)
● Published the book micrographia
unicellular vs multicellular organism
uni
- organism made up of only one cell
○ Euglena
○ Paramecium
○ Yeast
multi
- made up of many cell
○ Plants
○ Animal
○ Fungi
the unit measurement to measure the size of cell
micrometer
the unit used is 1um = 1/1000
- cell vary in size
- most r v small, some may be v large
size of cell
index card
shape of cell
index card
Which microscopes have been used to study the detailed structure of a cell?
compound microscope and the electron microscope.
*certain structures can be seen only under an electron microscope
structures of cell that can be only observed through electron microscope
ultrastructure
(the tiny parts inside a cell that are so small they can only be seen with a powerful electron microscope)
animal cell vs plant cell
index card
prokaryotic vs eukaryotic
index card
Union of sperm cell (male gamete; spermatozoon) and the ovum (female gamete)
fertilization
Multiplication of fertilized ovum and differentiation of its prognosis eventually gives rise to an extremely complex organism that consist of staggering number of cells
mitosis
[ a single cell divides to create two identical cells. Over time, these cells change into different types (differentiation) to form the many parts of a complex organism, like the brain, heart, and muscles.]
Clumps of cells that perform the same general functions are linked together by some amount of intercellular material and/or cell-to-cell junctions.
tissue
Bond of tissued in varying proportion to form more complex function
organ
Organs that have interrelated functions
organ system
cell wall
- tough, rigid and sometimes flexible
- made up of cellulose, hemicellulose and pectin
- may be thick, thin or multilayered structure
- function: protection, structure, regulation, filtering
3 main parts of cell membrane/ plasma membrane
- head
- made of glycerol - 2 tail (hydrophobic an non-polar)
- one is straight (saturated fatty acids)
- other bent (unsaturated fatty acid - due to the type of bonds in the fatty acids) - strong bond
- held tgt by covalent bond
AKA AS plasmalemma
- semipermeable
- tiny molecules like O2 and CO2 can pass through
- seen under electron microscope as it is v thin: 8-10 nm
- separate cell from its surrounding and forms special connections w other cells
function of plasmalemma
maintain
- shapes and size
- homeostasis
protect internal contents of cell
provide binding site and receptors for enzymes and other substances
regulates entry and exit out of substances in and out of the cell
responsible for cell to cell recognition
Involved in cell-to-cell recognition, cell-to-cell adhesion and immunological response
cell protein
[allowing cells to identify each other, stick together, and defend against harmful invaders.]
Serve to stiffen and strengthen the cell membrane
cholesterol
what are polysaccharides made up of
glycoprotein + glycolipid = glycocalyx, cell coat
- Responsible for cell-to-cell recognition, cell-to-cell adhesion, and immunological response
control center of the cell
nucleus, aka data bank
- contains chromosomes and genes
- removal of it means cell death
- stains well w hematoxylin
- site of rRNA synthesis
nucleus is not present in
rbc and sieve tube cell
contains 1 nucleus:
contains many nucleus:
contains 1 nucleus: uninucleate
contains many nucleus: multinucleate (eg, skeletal muscle)
euchromatic vs heterochromatic
index card
Fluid content inside the nucleus
nucleoplasm
- viscous homogenous material
- network of chromatin fibers are connected
Contains stretches of nucleic acid called DNA
chromosomes
- made up of dna + nucleoproteins
- 46 chromosomes = 22 pairs f somatic and 1 pair of sex chromosomes
is the term used to refer to the chromosomes at interphase
chromatin
also known as the nuclear envelope
nuclear membrane
- surrounds the nucleus
- made up of 2 layers: perinuclear space and cisternae
this is only present during late interphase. It disappears during prophase and reappears only during late telophase
nucleolus
- inside the cell
- contains RNA to build proteins
- synthesize ribosomal subunits
3 region of nucleolus
nucleolar organizing region
pars fibrosa
pars granulosa
Jelly-like materials formed by 80% of water
cytoplasm
- present between the plasma membrane and the nucleus
- CONTAINS
cytosol: a clear liquid portion various particles
formed elements
> organelles
> inclusions
> fibrillar elements
what does cytoplasm do
Hosts important substances like ions (minerals), proteins, lipids, and carbohydrates.
It is where many vital chemical processes happen, helping the cell stay alive and function properly.
Produces energy through chemical directions - breaking down fats & carbohydrates
mitochondria
- where krebs triacarboxylic acid cycle takes place = ATP produced
- recycles and decomposes proteins, fats and carbs
- 0.5 to 1.0 in diameter and up to 10 micrometer long
- 2 membrane: outer and inner
- inside has matrix, contains enzyme
types of endoplasmic reticulum
index card
how can ribosomes be extinguished
high-magnification electron microscopy
cluster of ribosomes, link by mRNA
polyribosomes
how does ribosomes work
- Cell nucleus transcribes DNA into RNA
- The mRNA is transported to the cytoplasm
- Ribosomes bind to the mRNA and read the genetic code
- Ribosome link amino acids together in the order specified by the mRNA
- The amino acids grow into long chains called polypeptides
- The polypeptide fold into proteins
golgi apparatus
- made up of 5-8 stacjs of membrane sacs
- has 2 faces
cis: close to ER whr materials enter
trans: other end whr it ships out - produces secretory vesicles to transport materials
- make s the plasma membrane and lysosomes
how it works:
The Rough ER (RER) and Smooth ER (SER) make proteins.
These proteins are sent to the cis face of the Golgi.
Inside the Golgi, proteins travel through the stacks, where modifications (like adding sugars) occur to mature the proteins.
Finally, the trans face ships out the mature proteins to their proper places.
what happens if lysosomes explode
cell breaks down
hence it is also called suicide sac
lysosomes
- involved in
heterophagy: eat foreign material like bacteria
autophagy: self eating - found throughtout the cell n work best in acidic enviro (pH of 5)
- function: digestion, protection, recycling, cell death
what does vacuoles contain
- water solution and help plants keep their shape
- function:
storage
transport
waste management
cell shape
protection
it is the membrane bound organelles present near the nucleus
centrosome
- aka microtubule organizing center
- consists of 2 structure called centrioles
- they help form spindle fibers (which are like tiny ropes) that pull the chromosomes apart during cell division.
they are small cylindrical structures inside the centrosome
centrioles
- made of microtubules arranged in a special way
- help make cilia and flagella
what does cytoskeleton made up of
- microtubules and microfilaments that give shape and support
- functions:
shape
strength
hep cell move, include chromosomes during division
help cells perform impt task like division
difference btwn cytoskeleton, centrosome, and centriole
Cytoskeleton is the entire network that provides structure and movement.
Centrosome organizes the microtubules and controls where they go during division.
Centrioles are tiny parts inside the centrosome that help in division and cell movement.
