Cells Flashcards
define ‘eukaryotic cell’.
a cell that contains membrane bound organelles and genetic material in the form of a nucleus.
define ‘ultrastructure’
the detailed internal structure of a cell
describe 3 differences between a eukaryotic cell and a prokaryotic cell.
- eukaryotes have membrane bound organelles such as mitochandria
- eukaryotic cells have a nucleus which contains DNA, prokaryotes have a circular loop of DNA in their cytoplasm.
- prokaryotic cells have DNA in the form of plasmids outside of the nucleus, eukaryotic cells don’t have extra DNA.
define ‘prokaryotic cell’
a cell that contains no membrane bound organelles and no nucleus.
describe the process of production and trafficking of proteins.
- the mRNA is created in the nucleus
- the mRNA leaves the nucleus through a nuclear pore and attaches to a ribosome
- the ribosome in turn attaches to the membrane of the rough ER and synthesizes the protein.
- the membrane of the rough ER creates a vesicle around the protein and it travels to the golgi apparatus
- the vesicle fuses with the golgi apparatus’ membrane and the golgi body modifies the protein.
- the golgi then forms a secretory vesicle around the protein and it leaves the cell via the cell surface membrane.
name the three components of the cytoskeleton.
- actin filaments
- intermediate filaments
- microtubules
name the functions of the cytoskeleton in the cell.
ACTIN FILAMENTS: -help change the shape of a cell -stabilize cell shape -help change the shape of a cell INTERMEDIATE FILAMENTS -help change the shape of a cell hep divide cytoplasm during cell division MICROTUBULES -form cilia and flagella (9+2 arrangement) -divide chromosomes during cell division -help move larger molecules.
state 3 differences and 3 similarities between a plant and animal cell.
similarities:
- both have a nucleus
- both have mitochondria to produce ATP
- both have cell surface membranes
differences:
-plant cells have large permanent vacuoles
-plant cells have a cell wall, animal cells do not
-plant cells have chloroplasts for photosynthesis
describe and name the parts of a chloroplast.
a chloroplast has a double membrane
the inner membrane forms disks called thylakoids, these stack up to form grana.
the spaces in between grana are called stroma
describe and name the parts of a mitochondrion.
a mitochondrion has a double membrane, the inner membrane forms folds called the matrix.
each fold creates a gap called a cristae.
describe the structure and function of flagella.
structure - rigid, rotating, helical shaped tail. made from an element of the cytoskeleton called microtubles. arranged in a 9+2 arrangement. function - used to propel the cell
describe the structure and function of cilia.
structure - short, hair like structures that protrude from the cell surface membrane - they have the same internal structure as flagella. function - move in a wave like motion to move things across the cell membrane or move the cell itself.
describe the structure and function of the cell wall.
structure - a mesh like structure surrounding plant cells made of cellulose fibres. function - supports the cell when turgid also provides protection for the cell.
describe the structure and function of centrioles.
structure - a short bundle of microtubules held at right angles to each other. function - forms a spindle like structure that chromosomes travel along during nuclear division.
describe the structure and function of the plasma membrane.
structure - a thin, phospholipid bilayer surrounding a cell function - partially permeable, allows substances to pass in and out of the cell.
describe the structure and function of chloroplasts.
structure - a double membrane bound organelle consisting of stacks of thylakoids called grana linked by intergranal lamallae, surrounded by stroma. function - contain chlorophyll and are the site of photosynthesis in plant cells which is the process of turning light into energy.
describe the structure and function of lysosomes.
structure - spherical sacs containing digestive enzymes surrounded by a single membrane. function - digest worn out organelles and remove vacuoles after the process of phagocytosis.
describe the structure and function of mitochondria.
structure - a double membrane bound organelle that has a folded inner membrane creating cristae which form a matrix. function - the site of respiration in cells which produces ATP which powers most of the processes in the cell that require energy.
describe the structure and function of ribosomes.
structure - small organelles not bound by a membrane, consisting of of two subunits made of proteins and RNA. function - synthesize proteins
describe the structure and function of the golgi apparatus.
structure - a stack of membrane bound, flattened sacs. function - modifies proteins and packages them into vesicles which are then secreted from the cell.
describe the structure and function of the smooth ER.
structure - membrane bound sacs called cisternae, with no ribosomes attached. function - involved in the synthesis of lipids.
describe the structure and function of the rough ER.
structure - stacks of membrane bound sacs called cisternae. continuous with the outer nuclear membrane. they often have ribosomes on the cytoplasmic side. function - allow ribosomes to attach to their membrane, which then forms vesicles around the newly synthesized proteins.
describe the structure and function of the nuclear envelope.
structure - a double membrane surrounding the nucleus, with fluid in between them. it also contains pores. function - encloses the nucleus. contains pores which allow substances such as RNA to pass out of the nucleus.
describe the structure and function of the nucleolus.
structure - a dense, spherical structure within the nucleus. function - makes RNA and ribosomes.
describe the structure and function of the nucleus.
structure - contains chromatin, surrounded by the nuclear envelope. function - houses cells genetic material. chromatin contains the instructions for making proteins.
