3A Cells Flashcards
Nucleus structure and function
nuclear envelope with nuclear pores
chromatin (DNA and proteins)
nucleolus (produces ribosomes)
controls cell activity by controlling DNA transcription to make proteins
lysosome structure and function
round organelle with membrane
contains digestive enzymes (lysozyme)
Ribosome structure and function
No membrane, a large and a small subunit formed of proteins and RNA
It is the site where proteins are made
Rough endoplasmic reticulum structure and function
membranes enclosing fluid, with ribosomes covering the surface
it folds and processes proteins made at the ribosomes
Smooth endoplasmic reticulum structure and function
Membrane system enclosing fluid
Synthesises and processes lipids
Golgi apparatus structure and function
Group of flattened membrane bound fluid sacs
it processes and packages lipids and proteins
makes lysosomes
Mitochondrion structure and function
Oval shaped with a double, folded inner membrane (folds are called cristae) the matrix contains enzymes used in respiration
Site of aerobic respiration
Centriole structure and function
Hollow cylinders made of microtubules
involved with the separation of chromosomes during cell division
Protein synthesis
Proteins produced at the ribosome with a primary structure
Processed and folded in the RER
Transported in vesicles to the Golgi apparatus
Further processing eg adding sugars
Transported in vesicles to the cell membrane where the vesicles fuse and they are released through exocytosis
Draw a eukaryotic cell cell
nucleolus
nuclear envelope
RER and SER
golgi
Mitochondria
ribosomes
centrioles
lysosome
cell membrane
Draw a prokaryotic cell
Free floating circular DNA
plasmids
flagellum
ribosomes
cell membrane
cell wall
pili
capsule
mesosomes
Differences between eukaryotic and prokaryotic cells
80S ribosomes in eukaryotes 70S in prokaryotes
Plasmids, flagella, cell wall of murein, capsule, mesosomes, pili are not found in eukaryotic cells
Structure and function of prokaryotic cells
flagellum- hair like structure improves motility
plasmids- small loops of DNA which can be passed between prokaryotes, can contain antibiotic resistant genes
circular DNA- no nucleus, free floating
cell wall- made of glycoprotein murein, supports the cell and keeps its shape
pili- small hair like structures which help cells stick together
capsule- secreted slime which protects from attack from the immune system
Mesosomes- inward folds of the plasma membrane with no apparent function
magnification equation
magnification= image/real
light vs electron microscopes
light- lower resolution so less detailed, can be used on living organisms
electron- higher resolution, larger magnifcation
cell organisation
Similar cells-> tissues -> organs -> organ system
tissues: a group of cells specifically adapted to work together to carryout a function
organs: a group of different tissues that work together
organ system: different organs working together to provide a function
Stages of mitosis
(I)PMAT
Interphase: DNA is unraveled and duplicated and cell organelles are duplicated
Prophase: The nuclear envelope breaks down, chromosomes condense and centrioles move to the poles
Metaphase: the chromosomes line up along the middle of the cell and spindle fibres attach to the centromere
Anaphase: spindle fibres shorten pulling the sister chromatids apart to opposite poles of the cell
Telophase: the chromosomes become long and thin again, nuclear envelopes form around each group. cytokinesis occurs and the cytoplasm splits into tw forming two identical daughter cells.
How to prepare lab stained root tips
Cut off the tip of a growing root.
Add the root into 60°C hydrochloric acid for 5 minutes
Rinse with cold water and dry
Place on slide
Cut off 2mm of the tip and macerate with mounted needle
Add toluidine blue stain + cover slip
mitotic index: definition and equation
The proportion of cells undergoing mitosis
mitotic index= number of cells with visible chromosomes/total number of cells
