section 2 cell structure Flashcards
what are cells adapted to do
cells are adapted to perform a particular function. Depending on that function, each cell type has an internal structure that suits it for its job
This structure can be known as ultrastructure
what are some differences with eukaryotic and prokaryotic cells
eukaryotic cells have a distinct nucleus and possess membrane bounded organelles. This differs with prokaryotic cells
what is the best microscope to use in order to see the structures of the organelles within a cell
an electron microscope is the best to use
high resolution
what are some important structures within an eukaryotic cells
Important structures are: 1.nucleus mitochondrion 3.chloroplasts 4.endoplasmic reticulum 5.Golgi apparatus 6.lysosomes 7.ribosomes 8.cell wall 9.vacuoles
(some of these are from plant cells)
what is the nucleus
the nucleus is the most prominent feature of a eukaryotic cell.
The nucleus contains the organisms hereditary material and controls the cell activities
how does the nucleus looks like
the nucleus appearance:
- usually spherical
- between 10 and 20 micrometers in diameter
- has a number of different parts
what is the nucleus function
- the nucleus acts as the control centre of the cell through the production of of mRNA and tRNA (and hence protein synthesis)
- retains the genetic material of the cell in the form of DNA and chromosomes
- manufactures ribosomal RNA and ribosomes
what are the different parts of the nucleus
there are many different parts in the nucleus:
- nuclear envelope
- nuclear pores
- nuclearplasm
- chromosomes
- nucleolus
what is the function of the nuclear pores
they allows the passage of large molecules, such as messenger RNA, out of the nucleus
what are the features of nuclear pores/ how do they look like
There are typically around 3000 pores in each nucleus, each 40-100nm in diameter
(they are around the nucleus)
what are the features of the nuclearplasm/ how do they look like
the nuclearplasm has granular, jelly like material that makes up the bulk of the nucleus (much like the cytoplasm)
what are chromosomes
Chromosomes consists of protein bound, linear DNA
what is the features of the nucleolus/ how do they look like
the nucleolus is the small spherical region within the nucleoplasm
what is the nucleolus function
It manufactures ribosomal RNA and assembles the ribosomes. There may be more than one nucleolus in a nucleus (depends on the cells function).
what is the function mitochondrion
the mitochondrion are the sites of the aerobic stages of respiration.
Therefore responsible for the production of the energy carrier molecule ATP, from the respiratory substrates e.g. glucose
what are respiratory substrates
a respiratory substrate is any organic molecule broken down to release energy for the synthesis of ATP
how do the mitochondria look like
they are usually rod like in shape
around the organelle is a double membrane that controls the entry and exit of material. The inner of the two membranes is folded to form extension known as cristae
what are the features of the cristae/ what are they
cristae are extensions of inner membrane, which in some species extend across the whole width of the mitochondrion.
what is the function of the cristae
they provide a large surface area for the attachment of enzymes and other proteins involved in respiration
what is the matrix
the matrix makes up the remainder of the mitochondrion
what does the matrix contains
it contains:
- proteins
- lipids
- ribosomes
- DNA
what are the chloroplasts
organelles are functions that carry out photosynthesis
how do chloroplasts look like
chloroplasts vary in shape and size but are typically disc shaped
2-10 micrometres and 1 micrometre in diameter
what are the different features of the chloroplasts ( the internal structure)
chloroplast envelope
the grana
the stroma