cells, biomolecules and carbohydrates Flashcards
Understand the basics of cell theory, and the reasons why all life is cell-based. Be able to identify the key features of eukaryotic and prokaryotic cells. Learn the structure of cellular organelles and components and how it relates to their function. Know differences between LM, SEM and TEM Familiarise yourself with the main classes of biological molecules, with emphasis on macromolecules Understand the concept of monomers and polymers, and how macromolecules are formed and broken down (co
1
Q
what are the 4 main principles of the cell theory?
A
- Structural and functional unit of all living things
-Cells come from pre-existing cells by division
-Contains hereditary info, this is passed from cell to cell during division
-Cells are small because they require a high surface-area ratio
2
Q
what are the main categories of cells?
A
- prokaryotic = bacteria and archaea
- eukaryotic = protists, fungi, animal and plant
3
Q
what’s the difference between eukaryotic and prokaryotic?
A
- prokaryotic has no membrane bound organelles sand eukaryotic has membrane enclosed organelles
4
Q
what is a cell membrane?
A
- also known as plasma membrane ; its a thin membrane which surrounds living cells; its semi-permeable.
5
Q
what is the nucleus?
A
- contains most of the DNA in eukaryotes; may also be in mitochondria and chloroplasts
- produces ribosomes
6
Q
what is the cytoskeleton?
A
- helps support the cell structure; consists of microtubules, intermediate fibres and microfilaments
7
Q
what are ribosomes?
A
- they exist free in cytoplasm and are bound to endoplasmic reticulum
- site of protein synthesis
8
Q
what is mitochondria?
A
- site of aerobic respiration; generates ATP from substrates; in all eukaryotic cells
- mitochondrion is usually 1-10um long
9
Q
what is the endomembrane system?
A
- a group of membranes, cisterns and vesicles
- works together to modify, package and transport lipids and proteins (eukaryotic)
- also includes nuclear envelope, lysosomes and SER and RER.
10
Q
what is endoplasmic reticulum; define the two types
A
- smooth ER = doesn’t have ribosomes on the surface and it synthesises and processes lipids
- rough ER = covered in ribosomes; helps fold and process proteins
11
Q
what are lysosomes made by and what does it contain?
A
- made by Golgi apparatus
- contains digestive enzymes
12
Q
what are peroxisomes?
A
- Membrane bound organelle; involved in lipid and fatty acid breakdown
13
Q
what are chloroplasts?
A
- only in plants
- site of photosynthesis
14
Q
what is photosynthesis?
A
- light energy is converted to chemical energy—> resulting in production of oxygen and energy rich organic compounds
15
Q
what are vacuoles?
A
- fluid filled, enclosed structures
- found in mostly plants and fungi but can be found In some protists, bacteria and animal cells
- function = maintaining cels turgor and isolating unwanted chemicals
16
Q
what are cell walls made of in plants, fungi and bacteria?
A
- plants = cellulose
- fungi = chitin
-bacteria = peptidoglycans
17
Q
how can we look at cells?
A
- light microscope
- electron microscope
18
Q
what does light microscopy help us do?
A
- look at structures such as plant cells etc
19
Q
what types of electron microscopes are there and what are they useful for?
A
- SEM (scanning electron microscope) = 3d picture
- TEM (transmission electron microscope) = good for viewing organelles inside the cell
20
Q
what substances are found in living tissues?
A
- mainly water and macromolecules with some ions + small molecules
21
Q
what large biological molecules are living things made up of?
A
- carbohydrates
- lipids
- proteins and nucleic acids
22
Q
what is meant by a polymer?
A
- a long molecule which consists of many similar monomers
23
Q
how are polymers formed?
A
- formed by monomers joining together and losing water molecules (loses 1 water molecule per bond) —> this is called a condensation reaction.
24
Q
how are polymers broken down?
A
- hydrolysis –> addition of water molecules
25
what are carbohydrates important for?
- energy (glucose needed for respiration)
- energy storage
- building macromolecules
- prevents protein breakdown for energy
26
what are carbohydrates?
- organic molecules which have a general formula of Cn(H2O)n
27
what can carbohydrates be classed as?
- sugar/polysaccharides
28
what can sugar be classified into?
monosaccharides
disaccharides
29
what is a monosaccharide?
- simple sugar, soluble
30
what is a disaccharide?
- two simple sugars linked by covalent bonds, also soluble
31
what is a polysaccharide and what can it be classified into?
- polysaccharide = tens to thousands of monosaccharides
- can be classified into storage and structural
32
how are polysaccharides formed?
- formed by the formation of glycosidic bonds
33
what is sugar?
- small, soluble molecule, source of energy in cellular metabolism (i.e. glucose)
34
what is sugar important for?
- synthesis of other essential molecules
- cellular recognition and signalling
- reducing vs non reducing sugars
35
what is an isomer? what significance does it have?
- a molecule with the same chemical formula but has a different structure
- different structures can impact its function due to its bond angles.
36
what is alpha/beta glucose?
- different isomers of the SAME molecule
37
what is cellulose and what is its function?
- beta glucose polymer
- structural, gives cell walls strength
38
what is starch and what is its function?
- alpha glucose polymer
- metabolic / energy storage
- less compact than cellulose (branching)
39
what is glycogen? what is its function?
- alpha glucose polymer
- metabolic (energy storage)
- more branching than starch which makes its solid deposits more compact than starch
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