Cell Structure Flashcards
Three main ideas of cell theory
• All living organisms are made up of one or more cells
•Cells are the basic functional unit in living organisms
• New cells are produced from pre-existing cells
All cells:
surrounded by a membrane
contains genetic material
have chemical reactions occur within the cell that are catalysed by enzymes
Define magnification
How many times bigger the image of a specimen observed is compared to its actual size
Convert mm to micrometers
x1000
convert micro meters to nm
x 1000
convert nano meters to micro metres
divided by 1000
How to use a scale bar
1) use a ruler and measure length of scale bar convert to mm
2) convert measurements to same units as used on scale bar
3) put in formula
measured length of scale bar / scale bar labelled
Define Resolution
The ability to distinguish between objects that are close together
Factors of light microscope
• Uses light to form an image
• maximum resultion 0.2 micro metres
• cannot be used to observe smaller organelles
• maximum magnification x1500
Factors of electron microscope
• Uses electrons to form an image
• maximum resolution 0.0002 micrometers
• can be used to observe smaller organelles
• maximum magnification x1500000
• specimens needs to be dead
Explain immunofluorescence
involves the use of antibodies that have been prepared with fluorescent dyes which bind with target molecules , allowing specific molecules to be detected
Explain freeze - fracture
a sample rapidly frozen using liquid nitrogen and then physically broken apart in a vacuum
Explain Cryogenic electron microscopy
• Involves flash freezing solutions
• Frozen solutions exposed to electrons to produce images of molecules
What ribosomes do prokaryotic cells have
70E
Ribosomes Function
Binding and Reading of mRNA during translation to produce proteins
Plasma membrane functions
Controls what enters and exits the cell
Function of cell wall
protection and maintains shape
What are the key structures animal and plant cells share ?
membrane -bound organelles
larger ribosomes (80S)
What are the key differences between animal cells and plant
animal cells contain centrioles and micro villi
plant cells have a cell wall
Facts about Rough ER
• Found in plant and animal
• Surface covered in ribosomes (80S)
• Processes proteins made by ribosomes)
Facts about Golgi Apparatus
• Found in plant and animal cells
• Modifies proteins and lipids before packaging them into golgi vesicles
Facts about vesicles
Found in Plant and animal cells
A membrane bound sac for transport
Fact about Lysosomes
breaks down waste materials
Facts about Cebtrioles
hollow fibres made of microtubules
found in all eukaryotic
What are the 7 functions unicellular organism carry out to stay alive
Metabolism
Reproduction
Sensitivity
Growth
Response
Excretion
Nutrition
3 exceptions to the cell theory
Skeletal muscle
Giant algae
Aseptate fungi
Differences between catabolism and anabolism
Catabolism breaks down big complex molecules into smaller molecules
Anabolism builds molecules required for the body’s functionality
What’s a hydrolysis reaction
uses water to breakdown polymers into monomers
Examples of monosaccharides
glucose
fructose
galactose
Examples of disaccharides
sucrose
lactose
maltose
Examples of polysaccharides
cellulose
starch
What makes up sucrose
glucose and fructose
What makes up maltose
glucose and glucose
Physical properties of monosaccharides
They can easily dissolve in water
They cannot be broken down into simple sugars
They are sweet in taste
Physical properties of disaccharides
They are polar compounds
They cannot diffuse through cellular membranes
They are soluble in water due to hydrogen bonding
Function of Starch
A way to store energy for plants
Function of glycogen
A reserve source of energy for the body providing quick energy when needed
Function of cellulose
structural support for plant cells
Structure of a triglyceride
Structure of starch
structure of cellulose
structure of glycogen
Functions of lipds
regulate hormones
transmit nerve impulses
transport nutrients
Define enzymes
a biological catalyst made up of large protein molecules
and speed up chemical reactions in the cell
How doe enzymes work?
reduce the activation energy thereby increasing the rate of reaction
3 factors that affect enzymes
temperature , pH , concentration
