B1.1 Cell Structures Flashcards
Eukaryotic cell
Cells whose genetic material is contained within a nucleus
Prokaryotic cell
Cells whose genetic material floats within the cytoplasms
Name the organelles ALL eukaryotic cells contain.
Nucleus
Cell membrane
Mitochndria
Cytosplasm
Name the EXTRA subcellular structures found in plants to animal cells.
Chloroplast
Cell Wall
Vacuole
Function of the nucleus
- Controlling the activities in the cell
- Contains the organisms genetic material, arranged as chromosomes
- Determines cells appearance and function
- The ‘power-house’ of the cell.
- Provides energy by respiration
Mitochondria
Function of the cell membrane
- Delicate surface membrane made of two layers of phospholipid
- Holds the cell together
- Controls what goes in and out of the cell
- Transfers energy, makes things, and stores food.
- Jelly-like substance where hundreds of reactions take place, which make up metabolism.
The cytoplasm
This cell type is complex and relatively large 10-100 μm
Eukaryotic e.g. plant & animal cells
Which English inventor and scientist where discovered cells using his self-designed microscope in 1665?
Robert Hooke
MRS GREN
M = ovement
R = espiration
S = ensitivity
G = rowth
R = eproduction
E = xcretion
N = utrition
This cell type is simple and typically smaller ~1-10 μm
Prokaryotic cells e.g bacteria cells
What are ribosomes and what is their function?
Ribosomes are tiny granules on the membranes in the cytoplasm.
Ribosomes are where proteins are made in the cell.
This organelle harnesses energy from the sun for photosynthesis
Chloroplast
What is a a vacuole and what is its function?
- Vacuole a large cavity filled with a watery fluid called cell sap.
- It helps keep the cell rigid, pushing outwards.
- This structure surrounds the cell.
- It is made of cellulose, a tough rubbery fibre.
- It gives the cell rigidity and supports the cell.
Cell wall
Name of primative bacteria-like organisms
Archaea
What is a plasmid and how can it be advantageous?
- A circular piece of DNA found in bacteria cells
- Not needed for day-to-day survival but can give the bacterium advantages such as antibiotic resistance
Tiny ‘hair-like’ structures that allow the cell to attach to structures, such a the cells in your digestive tract. They are also used to transfer genetic material between bacteria cells.
Pili
What is the function of a slime capsule?
- Protects bacteria from drying out and from poisonous substances.
- Helps bacteria to stick to smooth surfaces
List the structures and organelles you would expect to find in a bacteria cell.
- Cell wall (peptigoglycan)
- Cell membrane
- Flagella
- Single-loop DNA
- Plasmids
- Pili
- Cytoplasm
- Slime capsule
State three examples of commonly found bacteria
- Escherichia coli – Causes food poisoning
- Streptococcus – bacteria causes sore throats
- Streptomyces – bacteria found in soil and used to develop antibiotic streptomycin
Tail-like structures that allow bacteria cells to move through liquids
Flagellum
Name the parts of a light microscope
- Body tube
- Fine focussing knob
- Mechanical stage
- Stage
- Objectives
- Course focussing knob
- Revolving nosepiece
- Lens
- Mirror
- Arm
- Base
What is the equation for magnification?
Image size = Actual size x Total Magnification
Resolution
- The degree to which it is possible to distinguish between two objects that are very close together, rather than them look merged into one object.
- The higher the resolution, the greater the detail you may see
Name the two types of electron microscope
- Transmission electron microscope (TEM)
- Scanning electron microscope (SEM)
What are TEM used for and how have they advanced science?
- TEM is used to examine an extremely thin slice or section of cells or tissues
- TEM has revealed subcellular structures in cells not visible with a light microscope such as mitochondria and chloroplasts
What are SEM used for and how have they advanced science?
- SEM has a large depth of field so can be used to examine the surface structure of specimens.
- They produce a 3-D image of a surface by bouncing a beam of electrons off of a specimen.
What are the advantages and disadvantages of light microscope and electron microscopes?
Light microscope
- Cheep to buy and operate
- Small and portable
- Simple to prepare sample
- Natural colour of sample is seen unless staining is used.
- Specimens living or dead
- Resolution up to 0.2 µm
- (2 x 10-7 m)
Electron Microscope
- Expensive to buy and operate
- Large and difficult to move
- Sample preparation is complex
- Black and white images produced; false colour can be added to images
- Specimens are dead
- Resolution up to 0.1 nm
- (1 x 10-10 m)
