JLS310 – Exam preparation
Parts of a microscope
- Nosepiece houses the objectives.
- Coarse and Fine Focus knobs are used to focus the microscope.
- Stage is where the specimen to be viewed is placed.
- Stage Clips are used when there is no mechanical stage. The viewer is required to move the
slide manually to view different sections of the specimen.
- Aperture is the hole in the stage through which the base (transmitted) light reaches the
stage.
- Illuminator is the light source for a microscope, typically located in the base of the
microscope.
- Condenser is used to collect and focus the light from the illuminator on to the specimen. It is
located under the stage often in conjunction with an iris diaphragm.
- Iris Diaphragm controls the amount of light reaching the specimen. It is located above the
condenser and below the stage.
- Condenser Focus Knob moves the condenser up or down to control the lighting focus on the
specimen.
,Eukaryotic cell
1. Plasma membrane
Component Location
Phospholipids The main fabric of the membrane
Cholesterol Tucked between the hydrophobic tails of the
membrane phospholipids
Integral proteins Embedded in the phospholipid layer; may or
may not extend through both layers
Peripheral proteins On the inner or outer surface of the
phospholipid bilayer, but not embedded in its
hydrophobic core
Carbohydrates Attached to proteins or lipids on the
extracellular side of the membrane (forming
glycoproteins and glycolipids)
Include simple and complex sugars.
- Consists of monosaccharides
• They have carbonyl group and
multiple hydroxyl groups.
• Criteria for differentiating
simple sugars:
o Location of carbonyl
group; distinguishes a
simple sugar as Aldose or
Ketose
o Size of carbon skeleton,
ranges from 3-7 carbons
o Spatial arrangement
around asymmetric
carbons
- Disaccharides
- Polysaccharides
- 2 monosaccharides are joined
together by a covalent bond to form
a disaccharide
, Lipids
- Diverse group of hydrophobic molecules – based on their molecular structure.
• Fats
o Not polymers, but large molecules assembled from smaller molecules by
dehydration reactions.
o May be saturated or unsaturated.
• Phospholipids
• Steroids
2. Nucleus
3. Endomembrane system
, - Lysosomes: Digestive compartments
4. Mitochondrion
5. Chloroplast
Parts of a microscope
- Nosepiece houses the objectives.
- Coarse and Fine Focus knobs are used to focus the microscope.
- Stage is where the specimen to be viewed is placed.
- Stage Clips are used when there is no mechanical stage. The viewer is required to move the
slide manually to view different sections of the specimen.
- Aperture is the hole in the stage through which the base (transmitted) light reaches the
stage.
- Illuminator is the light source for a microscope, typically located in the base of the
microscope.
- Condenser is used to collect and focus the light from the illuminator on to the specimen. It is
located under the stage often in conjunction with an iris diaphragm.
- Iris Diaphragm controls the amount of light reaching the specimen. It is located above the
condenser and below the stage.
- Condenser Focus Knob moves the condenser up or down to control the lighting focus on the
specimen.
,Eukaryotic cell
1. Plasma membrane
Component Location
Phospholipids The main fabric of the membrane
Cholesterol Tucked between the hydrophobic tails of the
membrane phospholipids
Integral proteins Embedded in the phospholipid layer; may or
may not extend through both layers
Peripheral proteins On the inner or outer surface of the
phospholipid bilayer, but not embedded in its
hydrophobic core
Carbohydrates Attached to proteins or lipids on the
extracellular side of the membrane (forming
glycoproteins and glycolipids)
Include simple and complex sugars.
- Consists of monosaccharides
• They have carbonyl group and
multiple hydroxyl groups.
• Criteria for differentiating
simple sugars:
o Location of carbonyl
group; distinguishes a
simple sugar as Aldose or
Ketose
o Size of carbon skeleton,
ranges from 3-7 carbons
o Spatial arrangement
around asymmetric
carbons
- Disaccharides
- Polysaccharides
- 2 monosaccharides are joined
together by a covalent bond to form
a disaccharide
, Lipids
- Diverse group of hydrophobic molecules – based on their molecular structure.
• Fats
o Not polymers, but large molecules assembled from smaller molecules by
dehydration reactions.
o May be saturated or unsaturated.
• Phospholipids
• Steroids
2. Nucleus
3. Endomembrane system
, - Lysosomes: Digestive compartments
4. Mitochondrion
5. Chloroplast
