# 7 Flashcards
Smallest cell Mycoplasma size
diameter between 0.1 and 1.0 μm
Typical bacteria size
1-5 μm in diameter.
Ten times the size of the mycloplasms .
Eukaryotic cell size
10-100 μm in diameter
In order to stay alive, cells exchange resources, waste, and energy with their environments. This exchange happens across the cell membrane. As the volume of a cell increases, the ratio of surface area to volume decreases, making these exchanges less efficient. Some cells have folds in their membranes, which increase their surface area to volume ratio.
As a cell grows in size, the surface area gets bigger, but the volume gets bigger faster.
Surface area of volume is critical.
Why does smaller cell has grater ratio of surface area to volume?
As a cell increases in size,its surface area grows proportionately less than its volume .
(Area is proportional to a linear dimension squared,whereas volume is proportional to the linear dimension cubed)
Microvilli
increases surface area without an appreciable increase in volume.
Nucleus from in to out ….
Nucleolus
Chromatin
Nuclear Envelope
Nucleolus
non-membranous structure involved in production of ribosomes; a nucleus has one or more nucleoli.
Chromatin
material consisting of DNA and proteins;visible in a dividing cell as individual condensed chromosome.
Nucleus Envelope
double membrane enclosing the nucleus perforated by pores continuous with ER
Ribosomes
Bound in nuclear envelope
Golgi Apparatus
Organelle active in synthesis,modification ,sorting ,and secretion of cell products.
Centrosome
Region where microtubules are initiated ;contains a pair of centrioles.
Cell wall
Outer layer that maintains cells shape and protects from mechanical damage . made of cellulose ,other polysaccharides and proteins
Plasmodesmata
Cytoplasmic channels through cell walls that connects the cytoplasm of adjacent cells
Chloroplast
photosynthetic organelle,converts energy of sunlight to chemical energy stored in sugar molecules
Central vacuole
Prominent organelle in older plants cells;functions include storage ,breakdown of the waste products, and hydrolysis of macromolecules;enlargement of the vacuole is a major mechanism of plant growth.
Most of the genes are located in Nucleus
Yes some are in mitochondria and chloroplast
Nucleus size
5 μm in diameter
Nuclear envelope is a double membrane .The two membrane ,each lipid bilayer with associated proteins are separated by the space
20-40 nm.
Envelope pore structure
100 nm in diameter
Pore complex
An intricate protein structure lines each pore and plays an important role in the cell by regulating the entry and exit of proteins and RNA’s,as well large complexes of macromolecules
except the pores the nuclear side of the envelope is line by the nuclear lamina[net like array of proteins filaments in animal cells called as intermediate filaments that helps in maitaining shape of the nucleus by mechanically supporting the nuclear envelope]
The nuclear lamina with its nuclear pores forms the outer boundary of the nuclear matrix
Nuclear matrix
a framework of proteins fibers extending throughout the nuclear the nuclear interior .