Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > 2.1.2: Cell Structure > Flashcards

2.1.2: Cell Structure Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What are stains?

A

Coloured chemicals that bind to molecules in or on the specimen, making the specimen easy to see

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is differential staining?

A

When stains bind to specific cell structures, staining each structure differently so the structures can be easily identified within a single preparation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name 4 stains and what they do

A
  • Acetic orcein binds to DNA and stains chromosomes dark red
  • Eosin stains cytoplasm
  • Sudan red stains lipids
  • Iodine in potassium iodide solution stains the cellulose in a plant cell walls yellow and starch blue/black (but it appears violet under the microscope)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are artefacts?

A

Artefacts are visible details that aren’t part of the specimen being observed and have been made during processing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain steps involved in preparing permenantly fixed slides in light microscopy

A
  • Specimens are dehydrated
  • Then they are ambedded in wax to prevent distortion during slicing
  • Then a special instrument is used to make very thin slices called sections
  • These are then stained and mounted in a special chemical to preserve them
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the following for light microscopes
Magnification
Resolution
Radiation used
Focused by
Type of material that can be viewed
Size
Vacumm
Specimen made visible by
Colour

A

Magnification= High (x1500)
Resolution= Low (200 nm)
Radiation used= Light
Focused by= Optical/glass lenses
Type of material that can be viewed= living, moving, dead and abiotic
Size= Small + portable
Vacumm= Not necessary
Specimen made visible by= Using a stain
Colour= Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Technique, advantages and disadvantages of light microscopy

A

Technique- Light passes through the specimen into the magnifying lenses of the microscope into the objective viewing lenses into the eye
Advantages
* Relatively cheap
* Easy to used
* Study living specimens
* Portable- used in field and lab

Disadvantages
* Low resolution and limited magnification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the following for laser scanning confocal microscopes
* Magnification
* Resolution
* Radiation used
* Type of material that can be viewed
* Vacumm
* Specimen made visible by
* Colour

A
  • Magnification- High, x2000
  • Resolution- High but varies about 800nm
  • Radiation used- Light (laser)
  • Type of material that can be viewed- Living, used in medical research, components in cells
  • Vacuum- Not necessary
  • Specimen made visible by- Dyed with flourescent dye
  • Colour- Yes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Technique, advantages and disadvantages of laser scanning confocal microscope

A

Techniques- Uses a laser beam to scan an object pixel by pixel, creating a 3D image of the reflected photons. 2D imaged of higher resolution can also be produced

Advantages-
* Non-invasive
* allows for observation of 3D images

Disadvantages
* Expensive
* Time-consuming
* Only see flourecent object
* Flourescence can cause aretefacts
* Requires a compromise between resolution, scan time and photodestruction of the specimen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the following for scanning electron microscopes
* Magnification
* Resolution
* Radiation used
* Type of material that can be viewed
* Vacumm
* Specimen made visible by
* Colour

A
  • Magnification- High, not as good at TEM, x200 000 to x1 000 000
  • Resolution- 3-20nm
  • Radiation used- Electron beam
  • Type of material that can be viewed- Surface of cells and organisms
  • Vacumm- Yes
  • Specimen made visible by- Stained with heavy metals (specifically gold)
  • Colour- No
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Technique, advantages and disadvantages of scanning electron microscope

A

Technique- Beam of electrons is sent across surface of specimen and electrons that are reflected from the surface on the specimen are detected

Advantages-
* Produce 3D images
* High magnification and resolution

Disadvantages-
* Only non-living specimens
* Large and expensive
* Need skill and training to use
* Specimens can be damaged and aretfacts can be formed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the following for transmission electron microscopes
* Magnification
* Resolution
* Radiation used
* Type of material that can be viewed
* Vacumm
* Specimen made visible by
* Colour

A
  • Magnification- highest, x1 000 000
  • Resolution- 0.2nm
  • Radiation used- Electrons
  • Type of material that can be viewed- Ultrastructure, dead specimens, thin specimens
  • Vacumm- Yes
  • Specimen made visible by- Stained with metal salts
  • Colour- No
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Technique, advantages and disadvantages of transmission electron microscope

A

Technique- Beam of electrons is transmitted through a specimen and focused to produce an image

Advantages- High magnification and resolution

Disadvantages
* Only dead specimens
* Large and expensive
* Need skill and training to use
* Artefacts are likely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Structure of a nucleus

A

Surrounded by a double membrane nuclear envelope with nuclear pores.

Contains chromosomes, consisting of protein-bound, linear DNA, and one or more nucleolus.
Contains chromatin (the genetic material)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Function of a nucleus

A
  • The nuclear envelope sperates contents of the nucleus from rest of cell
  • The pores enables larger substances to leave nucleus or enter the nucleus
  • Chromosomes contain organism’s genes
  • DNA replication and transcription occur in the nucleus.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Structure of the nucleolus

A

Spherical structure found in the cell’s nucleus and does not have a membrane around it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Function of the nucleolus

A
  • site of ribosome production, produces and assembles ribosomes which then carry out protein synthesis
  • site of rNA production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Struncture of a chloroplast

A
  • Surrounded by a double membrane.
  • Contains thylakoids, which are folded inner membrane containing chlorophyll pigments.
  • Thylakoids stack to form structures called grana
  • Grana are joined together by lamellae (thin and flat thylakoid membranes)
  • Contains a fluid centre, the stroma.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Function of a chloroplast

A
  • The site of photosynthesis.
  • The light-dependent stage takes place in the thylakoids
  • The stroma contains enzymes for the light-independent stage of photosynthesis.
20
Q

Structure of a mitochondrion

A
  • Double membrane organelle.
  • The inner membrane is folded to form cristae.
  • Contains a fluid centre called the matrix.
21
Q

Function of a mitochondrion

A
  • Site of aerobic respiration and ATP production.
  • Self-replicating so more can be made if energy needs increase
  • Abundant in places of high metabolic activity
22
Q

Structure of a lysosome

A
  • Vesicles formed from the Golgi
  • Contain hydrolytic enzymes, often lysozyme.
  • Surrounded by a signle membrane
23
Q

Function of a lysosome

A
  • breakdown and digest organelles, pathogens and cells
  • Keep hyrolytic enzymes seperate from rest of cell
24
Q

Structure of Golgi Vesicles

A
  • Membrane-bound, fluid filled vesicles, located in the cytoplasm
  • Small, round, seen in high density near golgi sacs
  • Lysosomes are a type of golgi vesicle
25
Q

Function of golgi vesicle

A
  • Store and transport modified proteins and lipids from golgi apparatus to target cells
26
Q

Structure of the smooth endoplasmic reticulum

A
  • System of membranes, containing fluid filled cavities (cristernae)
  • Continuous with the nuclear membrane
  • No ribosomes of its surface
27
Q

Function of the smooth endoplasmic reticulum

A
  • Contains enzymes that catalyse reaction involved in lipid metabolism
  • Involved in the production, processing and storage of lipids, carbohydrates and steroids
28
Q

Structure of rough endoplasmic reticulum

A
  • System of membranes, containing fluid-filled caveties (cisternae)
  • Continuous with the nuclear membrane
  • Coated with ribosomes
29
Q

Function of rough endoplasmic reticulum

A
  • Intracellula transport system- cisternae form channels for transporting substances from different areas of the cell
  • Provides large surface areas for ribosomes
  • Ribosomes assemble amino acids into proteins (site of proteinsynthesis)
30
Q

Structure of golgi apparatus/body

A

Stacks of membranes creating flattened sacs called cisternae, surrounded by small, round and hollow vesicles.

31
Q

Function of the golgi apparatus/body

A
  • Proteins and lipids are packaged and modified here.
  • Carbohydrates can be added to proteins to form glycoproteins.
  • Finished products are transported in the Golgi vesicles.
32
Q

Structure of centrioles

A
  • Cyindrical shape
  • Made up of parallel microtubules that surround a central cavity
  • In most eukaryotes, they’re found in pairs that are arranged at right angles to one another
  • Only found alone when in the basal regions of cilia and flagella
33
Q

Structure and function of cilia

A

Structure - Hair-like projections out of cells.
Function - Can be mobile or stationary.
Mobile cilia help move substances in a sweeping motion.
Stationary cilia are important in sensory organs, such as the nose.

34
Q

Structure and function of flagella

A

Structure - Whip-like structure.
Function - For mobility, and sometimes as a sensory organelle for chemical stimuli.

35
Q

Structure of the cytoskeleton

A
  • A network of fibres found within the cytoplasm all over a cell.
  • Consists of microfilaments, microtubules and intermediate fibres.
36
Q

Function of the cytokeleton

A
  • Provides mechanical strength to cells, and helps maintain the shape and stability of a cell.
  • Many organelles are bound to the cytoskeleton.
  • Microfilaments are responsible for cell movement.
  • Microtubules are responsible for creating a scaffold-like structure.
  • Intermediate fibres provide mechanical strength.
37
Q

Structure of the plasma membrane

A
  • Consists of a phospholipid bilayer with proteins and cholesterol embedded within it.
  • Glycolipids and glycoproteins are located on the surface.
38
Q

Function of the plasma membrane

A
  • The fluid-mosaic model of the membrane refers to the fluidity and range of molecules in the
    membrane.
  • Cholesterol provides strength and reduces fluidity
  • Proteins are for transport
  • The glycoproteins and glycolipids are for cell recognition and act as receptors.
39
Q

Describe the pathway protein takes from production to secretion

A
  1. The nucleolus manafacturers ribosomes for protein synthesis in the rough endoplasmic reticulum
  2. The nucleus manafactures mRNA, which is needed by ribosomes to make proteins
  3. The ribosomes in the RER synthesise proteins
  4. The RER processes the proteins which are then sent in vesicles to the** golgi body**
  5. The** golgi body **further processes the proteins and sends them in vesicles to the plasma membrane
  6. The vesicles fuse with the **plasma membrane **to secrete the finished protein product
40
Q

How do you clibrate an eyepiece graticule?

A
  1. Line up stage micrometer and eyepiece graticule
  2. Count how many divisions of the eyepiece graticule fit into 1 division of the stage micrometer
  3. Each division on the stage micromete is 10 micrometers. So, 10 / divisions of the eyepiece graticule fit into 1 division of the stage micrometer = no, micrometers of 1 division of eyepiece graticule
41
Q

How to measure a cell

A
  1. Calibrate the microscope (each time you change the magnification)
  2. Line the cell up with the eye piece graticule scale
  3. Count the number of divisions in 1 cell
  4. Multiply number of division in 1 cell by number of micrometers 1 division is (as calaculated when calibrating)
42
Q

Magnification calculation

A

Magnification = image size/actual size (both in same unit)

43
Q

List for guidelines to follow when making an observational drawing

A
  1. Have a title
  2. The magnification must be recorded
  3. A sharp HB pencil should be used (and a good eraser!)
  4. On plain white paper
  5. Lines should be clear, single lines (no thick shading)
  6. No shading
  7. The drawing should take up as much of the space on the page as possible
  8. Well-defined structures should be drawn
  9. The drawing should be made with proper proportions
  10. Label lines should not cross or have arrowheads and should connect directly to the part of the drawing being labelled
  11. Label lines should be kept to one side of the drawing (in parallel to the top of the page) and drawn with a ruler
44
Q

Structure of a cell wall in a fungus, plant, bacterial or algal cell

A

Rigid covering that protects the cell.
What it’s made out of depends on the organism:
* Bacteria- murein (a type of glycoprotein)
* Plant- Cellulose
* Fungus- Chitin

45
Q

Function of a cell wall in a fungus, plant, bacterial or algal cell

A

Provide structural support and give shape to the cell

46
Q

Structure of a plant vacuole

A
  • membrane-bound sacs within the cytoplasm of a cell
  • contains a cell sap. The cell sap is a store of chemicals and mineral ions (including salts and sugars).
47
Q

Function of a plant vacuole

A
  • Maintains pressure by pushing the cytoplasm against the cell wall, which helps keep the plant cell turgid and prevents plants from wilting.
  • isolates harmful chemicals from the rest of the plant cell.

Biology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions