Topic 2: Foundations in Biology ❀ Flashcards
What are monomers?
Monomers are small absic molecular units
What three elements do all carbohydrates contain?
All carbohydrates contain carbon, hydrogen and oxygen
What are carbohydrates made from?
Carbohydrates are made from monosaccharides eg glucose, fructose and galactose
What is glucose?
Glucose is a hextose sugar - it has six carbon atoms in each molecule
What are the two types of glucose?
There is alpha glucose and beta glucose
What is a condensation reaction?
A condensation reaction is two molecules joining together with the formation of a new chemical bond and a water molecule is released when the new bond is formed
How are monosaccharides joined together?
Monosaccharides join together by condensation reactions
What type of bond forms between the monosaccharides in a condensation reaction?
A glycosidic bond forms between two monosaccharides in a condensation reaction as a water molecule is released
What is sucrose?
Sucrose is a disaccharide formed from a condensation reaction between a glucose molecule and a fructose molecule
What is lactose?
Lactose is a disachharide formed from a gluose and a galactose molecule
What are prokaryotes?
Prokaryotes are single celled organisms without a nucleus and do not have membrane bound organelles eg bacteria
What are eukaryotes?
Eukaryotes have membrane around their many complex organelles, they have a specific function and are part of multicellular organisms
What are the subcellular structures found in bacteria?
Bacterial cell subcellular structures:
- Flagellum/Flagella
- Pilli/Pillus
- Nucleoid (holds the DNA)
- Ribosomes
- Plasma membrane
- Cell wall thats made up of pepticlogycan
- Capsule/Slime layer
What is the mesosome in bacterial cells?
The mesosome in bacterial cells are the infolding of the plasma membrane, and are associated with DNA during cell division and helps with formation of new cell walls
Why is the capsule important in bacterial cells?
The capsule in bacterial cells provide additional protection
What is the role of the pilli in bacterial cells?
Pilli in bacterial cells are present for attachment to other cells or surfaces, and are involved in sexual reproduction
Size of prokaryotic cells
Size of bacterial cells = 0.1-10 micrometers
Size of eukaryotic cells
Size of eukaryotic cells = 10-100 micrometers
How does the filament that forms the flagellum gain energy?
The filament that forms the flagellum gain energy from chemiosmosis. The flagellum is attached to the cell membrane of a cell and gets rotated by a molecular motor.
What is the relative size of ribosomes determined by?
Relative size of ribosomes are determined by the rate at which they settle/form a settlement
Ribosome size in eukaryotes
Ribosome size in eukaryotes = 80S
Ribosome size in prokaryotes
Ribosome size in prokaryotes = 70S
Lipid droplets + Glycogen granules function in bacterial cells
Lipid droplets and glycogen granules provide as a nutrient store in bacterial cells
What are disaccharides?
Disaccharides are two sugar molecules joined together by a glycosidic bond.
What are reducing sugars?
Reducing sugars donate an electron to another molecule - they reduce molecules. All monosaccharides are reducing sugars, and some disaccharides
Why can prokaryotes still make proteins despite the lack of membrane bound organelles?
Prokaryotes have ribosomes, which are needed for protein synthesis. They float free in the cytosol. Ribosomes are not membrane bound.
Structural differences between prokaryotes and eukaryotes
-Eukaryotes have nucleus that’s surrounded by nuclear enevelope, prokaryotes doesn’t have a nucleus (it’s DNA floats free)
-Ribosomes of eukaryotes (80S) RIbosomes of prokaryotes (70S)
-Eukaryotes doesn’t have cell wall whereas prokaryotes has peptidoglycan cell walls
What is the cytoskeleton?
The cytoskeleton is an extensive network of protein fibres, with the two main types being microfilaments and microtubules
Microfilaments structure and function
-Solid strands mostly made up of the protein actin
-Can cause some cell movement and some movement of organelles
Microtubules structure and function
-Hollow strands mostly made up of the protein tubulin
-Organelles are moved along these fibres using ATP to drive their movement
Importance of the cytoskeleton
-Strengthening and support (holds the shape, and keeps organelles in place
-Intracellular movement (Aids transport by providing ‘tracks’ which organelles move eg during cell division)
-Cellular movement ((via cillia and flagella (which contain microtubules which are responsible for moving them))
Protein production process
1). Proteins synthesised on ribisomes on RER
2). Packaged into transport vesicles
3). Vesicles move towards golgi apparatus via cytoskeleton
4). Vesicles fuse with golgi apparatus, and they are modified
5). Vesicles fuse with plasma membrane and are released (exocytosis)
What are peptides?
Peptides are polymers made up of amino acid molecules - Proteins are made up of polypeptides arranged as complex macromolecules
Elements that make up protein
Elements that make up protein are carbon, hydrogen, oxygen and nitrogen
How do amino acids join together?
Amino acids join together by forming a peptide bond via a condensation reaction
Primary structure of proteins
Primary structure of proteins:
-Sequence of amino acids
-Directed by DNA
-Determines how polypeptides fold to give shape
-Peptide bonds only
Secondary structure of proteins
Secondary structure of proteins:
-Oxygen, hydrogen, nitrogen interacting
-Alpha helix: hydrogen bonds make them coil
-Beta helix: Polypeptide chains parallel to each other, joint by hydrogen bonds, makes a beta pleated sheet
Tertiary structure of proteins
Tertiary structure of proteins:
-Folds protein into final specific shape
-Includes section of secondary structure
-Coiling of sections brings in R groups so they interact
The different interactions that occur between R-groups
The interactions that occur between R-groups:
-Hydrophobic and hydrophillic interactions - weak interactions between polar and non-polar R-groups
-Hydrogen bonds (weakest bonds)
-Ionic bonds (forms between oppositely charged R-groups, stronger than hydrogen bonds)
-Disulfide bonds (covalent, strong, only occurs between R-groups that contain sulfur atoms)
Process of the biuret test for proteins
Biuret test for proteins:
1). Mix sample with equal volume of sodium hydroxide solution
2). Add copper sulfate slowly until sample turns blue
3) Mix solution and wait for results
Biuret reagent is a mix of an alkali and copper sulfate solution
Quaternary structure for proteins
Quaternary structure for proteins:
-Association of 2 or more individual different proteins (subunits)
What are the two groups that make up amino acids?
Amino acids are made up of an amine group and a carboxylic acid group
Synthesis of peptide
Synthesis of peptide:
Amine group of one amino acid + carboxylic group of another amino acid. The hydroxyl in the carboxylic acid and the hydrogen in the amine group is removed to produce water, and the peptide bond is formed
Paired student’s T-test
Paired student’s T-test = designed to compare the means of the same group/item under two seperate senarios
-Variation is assumed to not be equal
Unpaired student’s T-test
Unpaired student’s T-test = compares means of two independant/unrelated groups
-Variance is not assumed to be equal
