Cell Structure And Division Flashcards
Transmission electron microscope work by
Use electromagnetic to focus a beam of electrons which is then transmitted through the specimen. Denser parts of the specimen absorb more electrons so appear dark on the image.
Scanning electron microscopes work by
Scan a beam of electrons across the specimen. This knocks off electrons from the specimen which are gathered in a cathode ray tube to form an image.
Advantages and disadvantages of of transmission electron microscopes
Adv - high resolution
Dis - thin and dead specimen
Advantages and disadvantages of of scanning electron microscopes
Adv - thick specimens and 3D image
Dis - low resolution and dead specimens
Cell fractionation
Homogenisation:
Break up plasma membrane of specimen to release organelles into solution. Solution must be ice cold to reduce enzyme activity and be isotonic to prevent damage by osmosis. Add buffer to maintain pH
Flirtation:
Filter solution to separate tissue debris from organelles. Use gauze
Ultracentrifugation l:
Spin in centrifuge. Heavy settle at slow speed and increase
Mitosis in detail
Interphase:
DNA unravels and replicates. Organelles replicate. ATP increases
Prophase:
Chromosomes condense. Spindle forms. Nuclear envelopes breaks down and chromosomes lie free in the cytoplasm
Metaphase:
Chromosomes attach to spindle by centromere
Anaphase:
Centromeres divide. Spindles contract. Chromatids move to opposite piles
Telophase:
Chromatids uncoil and become chromosomes. Nuclear envelope forms.
Cytokinesis:
Cytoplasm divides
Mitosis steps
Interphase Prophase Metaphase Anaphase Telophase Cytokinesis
Absorption of glucose by cotransport
Sodium ions are actively transported out of the ileum into the blood by a sodium potassium pump
This creates a concentration gradient so sodium ions move from the blood into the ileum down its concentration gradient along with glucose across the sodium glucose co transporter protein.
This creates a concentration gradient as more glucose is in the ileum than the blood
Glucose diffuses out of the ileum into the blood down the concentration gradient via a protein channel by facilitated diffusion
Function of chloroplast
Site of photosynthesis
Function of the Golgi apparatus
Processes and packages lipids and proteins. Makes lysosomes
Function Golgi vesicle
Stores lipids and proteins made by Golgi apparatus and transports them out of the cell
Function of Lysosome
Contains lysozyme. Kept separate from the cytoplasm by the surrounding membrane and can be used to digest invading cells or to breakdown worn out components of the cell
Function of Ribosome
Site where proteins are made
Function of rough endoplasmic reticulum
Folds and processes proteins that have been made by ribosome s
Function of Smooth endoplasmic reticulum
Synthesises and processes lipids
Function of cell wall
Supports cells and prevents them from changing shape
Function of cell vacuole
Helped to maintain pressure inside the cell and keep the cell rigid. This stops plants wilting. Involved in the isolation of unwanted chemicals inside the body
Contains cell sap - weak solution of sugar and salts
Describe the structure of a prokaryotic cell
Cytoplasm Flagellum Free floating DNA Plasmids - loops of DNA Slime capsule Cell wall Cell surface membrane
Function of a slime capsule
Protect bacteria from attack by cells of the immune system
What do animal cells contain?
cell surface membrane rough endoplasmic reticulum nucleolus nucleus smooth endoplasmic reticulum lysosome ribosome nuclear envelope Golgi apparatus cytoplasm mitochondria
What do plant cells contain?
cell surface membrane rough endoplasmic reticulum nucleolus nucleus smooth endoplasmic reticulum ribosome nuclear envelope Golgi apparatus cytoplasm mitochondria chloroplast plasmodesmata vacuole cell wall
What do algal cells contain?
cell surface membrane rough endoplasmic reticulum nucleolus nucleus smooth endoplasmic reticulum ribosome nuclear envelope Golgi apparatus cytoplasm mitochondria chloroplast vacuole cell wall
What do fungal cells contain?
cell surface membrane rough endoplasmic reticulum nucleolus nucleus smooth endoplasmic reticulum ribosome nuclear envelope Golgi apparatus cytoplasm mitochondria chloroplast vacuole chitin cell wall
Function of a cell surface membrane
Regulates the movement of substances into and out of the cell. It also has receptor molecules on it, which allow it to respond to chemicals like hormones
