P1+2: Module 2: Foundations Flashcards
Mucus is composed of water, carbohydrates, proteins and triglycerides. Mucus is secreted by goblet cells. Suggest how the role of the GA is relevant to the function of goblet cells
Modify and package proteins into vesicles; so that they can be secreted via exocytosis
A theory suggests that mitochondria may have evolved from bacteria that mitochondria may have evolved from bacteria that were taken inside other cells. These cells then evolved into eukaryotes. Give 2 structural features of mitochondria that support this theory (2)
Contain 70s ribosomes; May have plasmids
Explain why early eukaryotes were able to grow more quickly than cells that didn’t possess mitochondria (3)
Cells w/ mitochondria can respire aerobically; which produces more ATP; ATP is needed for active transport
The plasma membrane contains proteins, which are made within the cell. Outline the process and organelles involved in the translation of these proteins from RNA (4)
mRNA transported out nucleus; mRNA transported to ribosome; translation occurs at ribosome; tRNA brings specific AA; peptide bonds form between adjacent AA
Describe 3 cellular functions of cytoskeleton
Provides mechanical strength; holds organelles in position/ place; aids in transport of cell eg cilia
Tubulin is a globular protein that can polymerise to form the cell cytoskeleton eg formation of microtubules. Suggest two ways tubulin is essential to protein synthesis and protein secretion in eukaryotic cells (2)
Movement of vesicles from RER to GA; movement of mRNA from nucleus to ribosome
State how cytoskeleton moves organelles around the cell
Uses microtubules
Explain how the function of epitheilal cells in airways of mammals in defence against pathogens and suggest the importance of the cytoskeleton carrying out this function (4)
Goblet cells secrete mucus; mucus traps pathogen; ciliated epithelium sweep mucus; cytoskeleton moves up cilia
A transmission e- microscope image of WBC was studied it concluded that the cell stopped dividing at G2 checkpoint. Suggest two observations that support this conclusion (2)
No visible chromosomes; Nuclear membrane present
Give 2 ways a drawing of a cell can be improved
-No shading/ cross hatching
-Add a title
-Add a scale
Explain how to measure the diameter of the nucleus of one WBC when observing cells through a light microscope (4)
Use eyepiece graticule; calibrate graticule using stage micrometer; measure diameter of nucleus; repeat and calculate mean diameter
Discuss the benefits of using a stain when making slides for light microscopes (3)
Provides contrast; so more internal structures are visible; because they bind to stain allowing a clearer image to be obtained
Explain the interrelationships between the organelles involved in the production and secretion of proteins. (9)
-A complimentary copy of the DNA is made in the nucleus
-The mRNA leaves the nucleus through a nuclear pore
-mRNA attaches to a ribosome
-Protein synthesis occurs
-The proteins are folded and processed at the rough ER
-The proteins are packaged into vesicles
-Transported to the golgi apparatus
-The vesicles fuse with the cis face of the Golgi apparatus and the proteins enter.
-The proteins are structurally modified at the Golgi apparatus.
-The proteins leave the Golgi apparatus on the trans side in a vesicle.
-The vesicles are moved to the plasma membrane by the cytoskeleton
-Proteins released by exocytosis
Resolution
The shortest distance between two objects that are still seen as separate objects.
Magnification
How many times bigger a microscope image is compared to the original specimen.
What are the correct uses for light microscope, TEM, SEM and laser scanning confocal microscope
-Light= whole cells and tissues
-TEM= organelles, 2D (denser parts look darker)
-SEM= cell surface, 3D
-Laser= object at a certain depth within a cell, 3D
Name one structure present in animal cells that aren’t present in plant cells
Centrioles
Ultrastructure
The detailed structure of cells visible only with an e- microscope
Name the carbohydrates molecules used to store energy in plants and animals
-Plants= starch
-Animal= glycogen
Describe and explain how the structure and properties of different carbohydrate and lipid molecules suit them to their role as energy storage molecules in plants and animal (9)
-CARBS; polymers of glucose- glucose used in respiration to release energy; large molecules- insoluble so doesn’t affect water pot. of cell; 1-4, GB- easy to hydrolyze to release glucose; coiled shape- compact so take up less space and can store more; glycogen more branched- allows more rapid release of monomers in animals
-LIPIDS; fats are insoluble- doesn’t effect water pot. of cell; fatty acids are long C chains- can be broken down to release 2 C groups; animal fats are saturated- used for insulation and energy storage
State a physical property of glucose that allows it to be easily transported in bloodstream
Glucose is soluble in water
Why do animals use glycogen instead of glucose (3)
Glycogen is insoluble so doesn’t affect water pot. of cell; its metabolically inactive and compact so lots can be stored in a small space
Give 3 properties of cellulose that make it suitable as the basis of cell walls
-Insoluble
-High tensile strength
-Flexible
Explain how the structure of phospholipids allow them to form a bilayer of plasma membrane
Hydrophillic heads + hydrophobic tails; hydrophobic tails repelled by water so face inwards: hydrophillic heads form H bonds w/ water so face outwards