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What are eukaryotic cells?
cells with a nucleus and other membrane-bound organelles
what organisms have eukaryotic cells?
plants, animals, fungi, protists
What do plant cells have that animal cells don't?
chloroplast, cell wall, large vacuole
What do animal cells have that plant cells don't?
lysosomes and centrioles
What is a prokaryotic cell?
cell that does not have a nucleus or organelles
what organisms have prokaryotic cells?
Bacteria and Archaea
what are organelles
specialised structures within a cell that perform specific functions.
What is the nucleus?
membrane-bound organelle that contains a cell's DNA
What does the nucleus do?
regulates cell activities such as gene expression and cell division.
What is the cell membrane?
a thin barrier surrounding the cell that controls the movement of substances in and out.
What are lysosomes?
small organelles filled with digestive enzymes
What does a lysosome do?
Uses digestive enzymes to rid the cell of waste
what is DNA made up of
nucleotides
What does DNA stand for?
deoxyribonucleic acid
what does RNA do?
holds genetic information and aids in protein synthesis.
What is resolution?
the ability to distinguish separate points or objects in an image
if I have a higher resolution provides what?
provides clearer and more detailed images.
what does TEMs stand for?
transmission electron microscopes
How do TEMs work?
use electrons transmitted through a specimen to create detailed images, particularly useful for studying internal cell structures
What does SEMS stand for?
scanning electron microscopes
How do SEMs work?
scan the surface of a specimen with electrons to produce detailed three-dimensional images, allowing examination of surface features.
how are animal cells are distinct from those of other eukaryotic cells
because the lack cell walls and chloroplasts and have smaller vacuoles (meaning it can transform into a variety of different shape)
What does the cell membrane do?
controls what goes in and out of the cell
the cell membrane is
Semi-permeable/Partially permeable/Selectively permeable
What is the cell membrane made of?
phospholipid bilayer
What does semi-permeable mean?
It will let some molecules through but not others
what does hydrophilic mean
Attracted to water
What does hydrophobic mean?
repels water
what does glycoproteins mean
any of a class of proteins which have carbohydrate groups attached to the polypeptide chain
What is cholesterol?
a compound of the sterol type found in most body tissues
What does extrinsic mean?
not part of the essential nature of someone or something
Is DNA single or double stranded?
double helix
Is RNA single or double stranded?
single stranded
What are the four nucleotide bases found in RNA?
cytosine, guanine, thymine, uracil / c,g,t,u
Which nucleotide base pairs with uracil in RNA?
Adenine (A)
What is the role of uracil in RNA?
Uracil is responsible for pairing with adenine in RNA during the process of protein synthesis.
What are the four nucleotide bases found in DNA?
Adenine, Thymine, Guanine, Cytosine / a,t,g,c
What is a nucleotide?
the whole structure of a DNA
What is a polynucleotide?
long chain of nucleotides
What does condensation reaction make?
water
What is a hydrolysis reaction?
a reaction in which a bond is broken by the addition of a water molecule
which nucleotide bases join together In DNA
c=g
a=t
which nucleotide bases join together in RNA
C=G
A=U
What is magnification?
How much bigger the image is that the specimen
What is magnification calculation?
size of image / size of real object
How many micrometers are in a millimeter?
1000 micrometers
How many nanometer are in a micrometer?
1000 nanometers
Plant cells have
chloroplasts and a cell wall surrounding it
plant cells are distinguished from most other cells by
chloroplast and one or more Lange vacuoles
Where is chloroplast found?
in certain algae in plant cells
plant cells enable the vacuole to
attain a large size without accumulating the bulk that would make metabolism difficult.
Where is cell sap found inside plants?
Inside the vacuole
What is cell sap?
A water solution of sugar and salts
How is the high concentration of cell sap maintained?
The high concentration of cell sap is maintained by the active transport of ions through the vacuole membrane.
What role does active transport play in maintaining cell sap concentration?
Active transport of ions through the vacuole membrane helps to maintain the high concentration of cell sap.
What is osmosis?
diffusion of water across a selectively permeable membrane
pros of TEMs
High resolution
Highest magnification
Gives information about surface features, shape, size and structure.
cons of TEMs
They're very big and expensive.
they are sensitive to mechanical vibration High maintains
Need a lot of materials in order to see anything
artifacts can be generated by sample preparation.
Special training is needed
Small space to see the material
pros of SEMs
Can build 3d images
sample does not need to thin
Gives artificial colouring
cons of SEMs
Artefacts are common
Black and white image
Specialist operators are required to operate electron microscopes
Expensive
inability to analyse live specimens
What is homeostasis?
Maintaining a stable internal environment
Examples of homeostasis
sweating and shivering
Homeostatic imbalances can lead to
diabetes, hypertension, and hypothermia.
what are the 5 things we need to keep a constant in our body
Water
glucose
Ph
body temperature
blood pressure
what happens when blood glucose is too high
Insulin is added and causes cells to take up more glucose
what does insulin do with the enzymes?
converts glucose to glycogen
What is glycogenesis?
formation of glycogen from glucose
what happens when blood glucose is too low
Glucagon is added
What does glucagon do?
activates enzymes in order to make glucose from glycerol and amino acids
What is gluconeogenesis?
the formation of glucose from glycerol and amino acids
Where does adrenaline come from?
adrenal gland
if blood glucose is too ____ Adrenaline is also secreted by adrenal glands
low
What is type 1 diabetes?
characterised by a lack of insulin production in the body, meaning high bsl
What is insulin?
Insulin is a hormone which converts glucose into glycogen (when blood sugar levels are too high)
Where does insulin come from?
pancreas
What is type 2 diabetes?
insulin resistance
how does the body try to deal with type 2 diabetes
the pancreas has to produce more insulin to try to regulate blood sugar levels,
Is type 1 or 2 diabetes more to do with lifestyle?
type 2
What is type 1 diabetes caused by?
an autoimmune attack on the insulin-producing cells in the pancreas
Is type 1 or type 2 diabetes less to do with lifestyle changes?
type 2
How is Type 2 diabetes managed?
diet and exercise
If you have glucose in your urine, what's responsible for it?
too much glucose
how can you detect if you have diabetes
urine dipstick
what is the kidneys' threshold for reabsorption
180 mg/dL
What is glycosuria?
glucose in the urine
What is osmoregulation?
The control of water balance.
How does the body lose water?
sweat
breathing out
urine
What is aldosterone?
a hormone produced in the cortex of the adrenal gland
What does aldosterone do?
Increases reabsorption of sodium and increases secretion of potassium, this helps lower blood pressure
what are the consequences of Salt Deficiency
Disorientation and Confusion
Muscle Cramp and Nausea
Severe Organ Damage
Stroke
how do we lose too much salt
too much water - can flush out sodium
excessive loss in body fluids
eating disorder
What does ADH do?
Facilitates reabsorption of water in kidney
What is ADH?
antidiuretic hormone
Where is ADH produced?
hypothalamus and released by the pituitary gland
Where does aldosterone come from?
adrenal gland
What affects photosynthesis?
light intensity, carbon dioxide, water supply, temperature
Photon of light + water
1/2o2 +2e- + 2h+
What happens when photosystem 2 is hit with a photon of light?
When photosystem 2 is hit with a photon of light, it gets excited and releases 2 high-energy electrons.
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