✅2: eukaryotic Flashcards
What is the nucleus
Contains DNA providing protein synthesis
What is the nucleolus
Contains DNA and information of RNA for constructing ribosomes
What are ribosomes
Site of protein synthesis
What is the rough endoplasmic reticulum
Attached ribosomes synthesise proteins and the ER transports proteins to the Golgi body
What is the smooth endoplasmic reticulum
Synthesis of lipids and steroids
What is the mitochondria
Site of the reactions of aerobic respiration and where ATP is made
What are centrioles
Guide the formation of spindle fibres during mitosis and meiosis
What are lysosomes
Contain hydrolytic enzymes that digest old organelles and bacteria etc
What is the Golgi apparatus
Modified and packages proteins synthesised in the cell
What is the cell wall
Supports plant cells and prevents them bursting when turgid
What is the chloroplast
Site of the reactions of photosynthesis, in which carbon dioxide and water are converted to carbohydrates
What is a vacuole
In plant cells, contains cell sap which is an aqueous solution of many different compounds
What is a tonoplast
the cell membrane surrounding the vacuole, which controls what enters and leaves it
Where are eukaryotic cells found
Animals, plants and fungi
What is gram positive and gram negative
When stained with gram stain, positive bacteria takes up the stain and looks our pole. Negative doesn’t. Positive has thick outer layer of peptidoglycan, which absorbs the stain. In negative, the cell wall lies between the two cell membranes. The outer membrane protects bacteria from several antibiotics
How do proteins end up on rough endoplasmic reticulum and Golgi apparatus
Proteins which are exported from a cell (extra cellular enzymes) are made on ribosomes attached to rER. Amino acids are strung together into a long chain on ribosome and joined together by peptide bonds. As chain forms, fed through the membrane of endoplasmic reticulum so protein ends up inside the space between the endoplasmic reticulum membrane.
What happens to the protein on rER.
Part of the cisternum, with the proteins in it, break off to form a membrane bound vesicles. The moves towards the Golgi apparatus. Vesicle fuses to the outer convex face of the Golgi apparatus.
What happens at the Golgi apparatus after the vesicles fuse?
Protein molecules are modified by having carbohydrate groups added to them to produce apparatus.
Where do the vesicles travel too after they break off the face of the Golgi apparatus
Travel to the cell surface membrane and their content (proteins) and depositors outside the cell
How do you observe cells?
Microscopes
Light and electron
What is a light microscope?
Thinly sliced material is placed on a stage of a light microscope. And illuminated from underneath. Objective lens produced a magnified and inverted image, which eyepiece lens focuses at the eye.
Total magnification of 100
what is bad about the light microscope?
preservation and staining the tissue can produce artifacts in the tissues being observed. most of the species are dead and stained. limited resolution and magnification.
what kind of dye can you use for light Microscopes?
haematoxylin- purple, blue or brown.
methylene blue- blue
acetocarmine- stains the chromosomes dividing
iondine- blue-black
what is the electron microscope|?
use beams of electrons to form an image. electrons are scattered by the specimen. electrons effectively behave like light waves. 10000 x better than a light microscope.
what are the two types of electron micrographs?
transmission electron micrographs which are 2D images like those on a light microscope. scanning electron micrographs have a lower magnification, but are 3D.
advantages of electron microscopes
huge power of magnification and resolution. many details in the cell structure.
disadvantages of electron microscopes
all specimens are looked at in a vacuum, the air would scatter the electrons and make the image look fuzzy. therefore they cannot be alive.
undergo several treatments that is likely to result in artefacts.
extremely expensive.
large, and needs constant temperature and pressure.
what are the functions of membranes?
forms boundary to the cell, controls what passes in and out. allows fluids either side to pass in or out. make it possible for the cell to have the right conditions.
many chemical processes happen on the cell membrane. eg, respiration takes place on the mitochondrial membrane. also needs to be flexible.
what is the phospholipid bilayer?
lipids in the membrane which are polar lipids. one end are joined to a polar group. many polar lipids in the membrane are phospholipids with a phosphate group attached to them, and with water or aq solutions on each side , pointing to the water, while hydrophobic tails stay protected inside the membrane. called a unit membrane.
what are membrane proteins?
proteins on the membrane. the more unsaturated fatty acids are, the more fluid the membrane. many proteins have a hydrophobic part, which is buried in the lipid bilayer,a d a hydrophilic part. some proteins penetrate the whole way through the membrane.
what are the functions of the membrane proteins?
help substances move across the membrane. proteins can form pores and channels, some are permanent or temporary, which allow specific molecules through. can be opened or shut depending on the conditions in the cell.
what are gated channels?
proteins in the cell membrane structure which allow molecules through. opened or shut depending on the conditions. some of the protein pores are active carrier systems using energy to move molecules.
what is the typical animal cell?
cell surface membrane, jelly like cytoplasm, with a nucleus. these 2 together form the protoplasm. cytoplasm contains whats needed for day to day living. nucleus is the survival of the cell, with the genetic make up.
what are the membranes in an animal cell?
internal (intracellular) membranes. they localize enzyme in reaction pathways.