Master this deck with 46 terms through effective study methods.
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Cell with a nucleus and membrane bound organelles (e.g. animal and plant cells).
A cell that does not have a nucleus (Ex. bacteria)
Those features that can be seen using a microscope.
- cell surface plasma membrane - rough endoplasmic reticulum (RER) - smooth endoplasmic reticulum (SER) - nucleus - nucleolus - nuclear pores - nuclear envelope - lysosomes - 80s ribosomes - Golgi apparatus - cytoplasm - mitochondria - centrioles
- cellulose cell wall (with plasmodesmata) - a large permanent vacuole - chloroplasts
- The membrane found on the surface of eukaryotic cells, composed of phospholipids and proteins. - Regulates movement of substances into and out of the cell. - Receptor molecules responding to chemicals and hormones.
- A rigid structure that surrounds plant cells. Mainly composed of cellulose - Supports plant cell turgor (prevents lysis).
The nucleolus is a spherical structure in the nucleoplasm that is a site for active ribosomal RNA synthesis.
Nuclear pores are passageways that allow chemical communication between the nucleus and cytoplasm, regulating the movement of ions and small molecules.
Nucleus contains DNA (genetic material) in the form of chromosomes that control the cell's activities.
A double membrane that surrounds the nucleus. Its outer membrane is continuous with the endoplasmic reticulum of the cell and often has ribosomes on its surface. It controls the entry and exit of materials in and out of the nucleus and contains the reactions taking place within it.
A vesicular membrane-bound organelle which contains digestive, hydrolytic enzymes that are used to digest invading species in phagocytosis.
A small (80s) non membrane-bound organelle composed of protein and rRNA which either: -floats free in the cytoplasm and synthesises intracellular proteins. -attached to the RER to synthesise extracellular enzymes. - the site of protein synthesis (both).
A system of membranes enclosing a fluid-filled space and is covered with ribosomes. They fold and process proteins that have been made by ribosomes.
The same as the RER, but without ribosomes attached. -Synthesises and processes lipids - Stores carbohydrates
A vesicle is a small membrane-bound sac that transports substances within or outside the cell.
The Golgi apparatus is a group of fluid-filled, membrane-bound sacs which modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles. It also synthesises lysosomes.
Double-membrane bound organelle with a folded inner membrane called cristae, with a fluid inside called the matrix. Has its own mDNA. It is the site of aerobic respiration producing ATP for metabolic activities.
Double-membrane bound organelle with interior membranes called thylakoid membranes. These membranes stack to form grana (granum) which are linked by lamellae. The interior fluid is called the stroma. These also have their own DNA. They are the site of photosynthesis.
A small hollow cylinder made of microtubles and is involved the the separation of chromosomes that happens during cell division
Cilia are surface extensions that move materials across the cell surface composed of an outer membrane and a ring of 9 pairs of micro tubules, with a single pair in the middle (9+2 formation). They move in a BEATING motion.
Flagella are long, hair-like structures that extend from the plasma membrane and are used to move an entire cell. They are used for cell propulsion and spin (eg. In sperm cells).
1. rRNA is made in the nucleolus which is used to synthesise ribosomes, ribosomes leave via nuclear pores and attach to the RER or float free in the cytoplasm. 2. Transcription occurs in the nucleus where mRNA leaves via nuclear pores and is translated at the ribosomes. 3. The ribosomes form the complementary amino acid sequence. 4. Amino acid sequence is processed by the RER and packaged into a transport vesicle which is sent to the Golgi apparatus. 5. The Golgi apparatus folds and processes the sequence into tertiary and quaternary proteins and then packages them into a secretory vesicle. 6. Secretory vesicle fuses with the cell surface membrane and is secreted via exocytosis.
Network of protein strands including: - Microtubules made of tubulin: facilitate transport of substances within the cell, facilitate cell division, facilitate locomotion and provide structural support. - Microfilaments made of actin: form a network to support cell shape, facilitate muscle contraction via myosin, enable cytokinesis and locomotion. -Intermediate fibres: enable mechanical strength and form cell junctions.
- Both have ribosomes - Both have cell surface membranes and cell walls. - Both have flagella - Both contain DNA
P: extremely small, E: larger P: Circular DNA, E: linear DNA P: No nucleus, E: Nucleus P: peptidoglycan cell wall, E: cellulose OR chitin P: Few membrane-bound organelles P: 70s ribosomes, E: 80s ribosomes
Magnification = size of image / size of object
1mm = 1000um = 1,000,000nm
How many times larger an image is than it is in real life.
How well a microscope distinguishes between two points that are close together/different organelles.
Light microscope Transmission electron microscope Scanning electron microscope
visible light passes through a specimen and then through glass lenses, which magnify the image
They use beams of electrons that are focused by magnetic fields.
TEM sends a beam of electrons through the specimen forming a 2D image, the SEM bounces electrons off the surface forming a 3D image.
Light < SEM < TEM
- Treat with a heavy metal ie. Lead (Pb) - Metal ions scatter to allow electrons to produce an image
methylene blue, safranin, crystal violet, Giesma
- Stains are absorbed more by certain parts than others, allowing for increased contrast between different parts of the micrograph.
To identify two different parts of a cell that are not usually visible or distinguishable in light microscopy... E.g. the cell wall and cell membrane.
1) get a THIN piece of the specimen and put on slide 2) cover specimen with a cover slip and observe on low magnification and high magnification
1) place specimen on microscope slide 2) add a drop of distilled water 3) place on end of glass coverslip to the right or left of the specimen so that the rest of the slip is held at a 45 degree angle over the specimen 4) slowly lower cover slip so you don't get air bubbles
1. Select the lowest power objective lens 2. Use the coarse adjustment knob to bring the stage to just below the objective lens. 3. Move the stage down until it's roughly in focus. 4. Use the fine adjustment knob until you have a clear image. 5. Repeat this process at higher magnifications using higher power objective lenses.
1. Eyepiece: to observe the specimen 2. Objective lense: to magnify the specimen 3. Stage: to move the specimen closer/further 4. Coarse adjustment knob: for large-scale focusing 5. Fine adjustment knob: for higher resolution focusing 6. Light: to pass light through specimen
Transparent ruler with numbers but no units fitted on the eyepiece of microscope
A millimeter long ruler etched onto a slide. it has 100 divisions, each of 0.01mm or 10 micrometers. It is used to calibrate the eyepiece graticule
First work out *how many units on the micrometer are equivalent to the units on the graticule scale* - E.g. 10 units on the micrometer scale are equivalent to 40 units Therefore you can work out *how much 1 unit on the micrometer scale is equal to on the graticule scale* - E.g. 1 unit on the micrometer scale equals 4 units on the graticule scale Then to find how much each unit on the graticule equals, *divide the length of one unit on the micrometer scale by how many units on the graticule scale is equivalent to 1 unit on the micrometer scale* - E.g. as each unit on the micrometer scale equals 10 μm, each unit on the graticule equals 10 ÷ 4 = 2.5 μm