3A: Cells Flashcards
What organelles are in a animal cell/eukaryotic cell? (12)
- nucleus
- nucleolus
- nuclear envelope
- rough endoplasmic reticulum
- smooth endoplasmic reticulum
- golgi apparatus
- cytoplasm
- mitochondrian
- ribosome
- lysosome
- cell surface membrane (plasma)
- centriole
what is the nucleus
a large organelle surrounded by a nuclear envelope and contains chromatin and a nucleolus
what is the function of the nucleus (and the DNA, the nuclear envelope and the nucleolus)
- controls the cells activities
- DNA from the chromatin contains instructions on how to make proteins
- the pores within the nucleus envelope allow substance to move between the nucleus and the cytoplasm
- the nucleolus makes ribosomes
what is a lysosome
a round organelle surrounded by a membrane
what is the function of a lysosome
the lysosome contains digestive enzymes which can be used to digest invading cells or break down worn out components of the cell
- these enzymes are kept separate from the cytoplasm by the membrane surrounding the lysosome
what is a ribosome
a small organelle made up of proteins and RNA
- it can be found either free in the membrane or attached to RER
what is the function of a ribosome
to make proteins
what is the rough endoplasmic reticulum (RER)
a system of membranes enclosing a fluid filled space - its surface is covered in ribosomes
what is the function of rough endoplasmic reticulum
it folds and processes proteins that have been made (translateda) at the ribosomes
what is smooth endoplasmic reticulum
a system of membranes enclosing a fluid filled space - has no ribosomes
what is the function of smooth endoplasmic reticulum
synthesises and processes lipids
what is golgi apparatus
a group of fluid filled, membrane bound, flattened sacs - vesicles are often seen at the edges of sacs
what is the function of golgi apparatus
it processes and packages new lipids and proteins - it also makes lysosomes
what are mitohondrian
oval shaped - has a double membrane ( inner membrane folded to form a cristae), has a matrix inside which includes enzymes ( used for respiration)
what is the function of mitochondrian
it is the site of aerobic respiration - it is where energy (ATP) is produced and provided for respiration
what is the centriole
small hollow cylinders made up of microtubes
what is the function of the centriole
involved in the separation of chromosomes during cell division
what are the oragnelles within a prokaryotic cell
- cell membrane
- circular (chromosonal) DNA
- plasmid DNA
- flagellum
- cytoplasm
- mesosome
- ribosome
- capsule
- pili
- murein cell wall
what is a mesosome
inward folds of plasma membrane
what is the cell capsule
secreted slime that surrounds the cell
what is the role of the cell capsule
helps to protect bacteria from attacks by cells of the immune system
what is pili
short hair-like structures attached to the cell
what is the role/function of pili
helps prokaryotes stick to other cells
- can be used to aid transfer of genetic material between cells
how does bacteria reproduce
asexually through binary fission
what is the process of binary fission
- genetic material of cell is replicated
- cell grows larger and each set of GM begins to move to opposite ends of the cell
- cell wall and cell membrane begin to divide to separate two sets of DNA
- cell wall and cell membrane close around each DNA set
- cell splits to form 2 identical cells
what are the main pieces of a microscope
eyepiece lens
objective lens
stage
stage clips
lamp
fine dial
course dial
base
what are the two types of microscopes
electron microscope and light microscope
key features of a light microscope
- can use living samples
- can view in colour
- cheap and accessible
key features of an electron microscope
- B&W only
- samples must be dead
- higher resolution and magnifiction than light microscope
- expensive
what are the two types of electron microscopes
Transmission electron microscopes (TEM) and Scanning Electron microscope (SEM)
what are Transmission electron microscopes and when were they discovered
discovered in 1931
- use beams of elctrons
- magnification up tp 50,000,000
- produce 2D images
- expensive
what are Transmission electron microscopes and when were they discovered
discovered in 1931
- use beams of elctrons
- magnification up tp 50,000,000
- produce 2D images
- expensive
what are scanning electron microscopes and when were they discovered
discovered in 1965
- uses electron beams
- magnification up to 1,000,000
- produce £D images
how to calculate magnification
size of image / size of real image
what is the body organisaton system
cells, tssues, organs, organ systems, organisms
what are tissues
groups of similar cells that all develop from the same kind of cell
what are the 4 main types of tissue
epitheilal tissue
muscle tissue
connective tissue
nervous tissue
what is epithelial tissue
lines internal and external surfaces
what is muscle tissue
shorten or contract to produce movement
what is mitosis
cell division that produces two genetically identical cells
what are the three functions of mitosis
growth
repair
asexual reproduction
what are the phases of mitosis
prophase
metaphase
anaphase
telophase
what are the phases of mitosis
prophase
metaphase
anaphase
telophase
what is the cell cycle
interphase, mitosis, cytokinesis
what happens during interphase
te cell prepares for division
- DNA unravels and is replicated
- organelles are replicated
- ATP content increases
- cell swells
what happens during prophase
chromosomes condense and becoming shorter and fatter - making them visible
- centrioles move to opposite poles of the cell
- network of protein fibres called the spindle develop
- nuclear envelope breaks down and chromosomes are free in cyto
what happens during metaphase
- spindle fibre attach to ccehromatids at the centromere
- chromatids line up at the middle of the cell
what happens during anaphase
– centromere divides hence separating the sister chromatids
- SF contract pulling chromatids to opposite poles
- uses energy provided from aerobic respiration in the mito
what happens during telophase
- chromatids uncoil and become long & thin (now chromosomes)
- nuclear envelope forms around each chromosome
- cytoplasm divides to form 2 daughter cells
