Starter questions Flashcards
Describe how macrophages process antigens for presentation on their cell surface membrane
Antigen fragments combined with MHC (special glycoproteins in cytoplasm)
What name is given to small protein molecules that act as cell-signalling compounds?
Cytokines
State three passive physical defences that prevent plants being infected by a pathogen
Bark, waxy cuticle, thorns, spines, lignified cell walls, cellulose.
State three factors that would affect the speed of disease transmission in plants
Overcrowding, poor mineral nutrition, damp warm humid conditions, climate change.
Describe the difference between herd vaccination and ring vaccination
Herd vaccination is where everyone (or almost everyone) is vaccinated. Ring vaccination is vaccinating people around the site of the outbreak, so that the pathogen will not be transmitted across that ring to the whole population.
Explain why passive immunity only provides short-term immunity
Passive immunity is provided by an external supply of antibodies - these are proteins and will not last long in the body. They may even act as antigens and be attacked by antibodies from our immune system
Antibodies are made by plasma cells. Explain how plasma cells are speciaised for their role.
Plasma cells have a lot of ribosomes, rough endoplasmic reticulum, golgi apparatus and mitochondria. Ribosomes for proteinsynthesis, golgi for vesicles.
Give an example of artificial active immunity
Immunity provided by antibodies made in response to vaccination (dead/inactive pathogens injected).
Describe how B lymphocytes are activated and the role of activated B lymphocytes
The cell binds specifically to B lymphocyte, B lymphocyte differentiates into a plasma cell. Plasma cells release antibodies specific to the particular antigen.
Describe how antitoxins function.
Neutralise toxin molecules released by a pathogen through direct binding.
Where is bile stored?
Gall bladder
What is negative feedback?
A response that is opposite to the stimulus, returning conditions back to the optimum
What are 3 advantages of being ectothermic that are disadvantages to being endothermic
Ectotherms: use less energy from food for respiration, use more energy from food for growth, survive long periods without food
Name 4 physiological responses in an endotherm that lead to a decrease in temperature
Piloerection, vasoconstriction, increased liver metabolism, shivering
What is vasoconstriction?
Contraction of smooth muscle to narrow arterioles which restricts blood to the skin surface
What 6 substances are reabsorbed in the proximal convoluted tubule?
Glucose, amino acids, water, mineral ions, vitamins, hormones
What methods are used to test for the presence of anabolic steroids in urine?
Mass spectometry & gas chromotography
What is the importance of selective reabsorption?
Get useful substances back into the body
Where is ADH produced?
Hypothalamus
What are the resident macrophages called in the liver?
Kupffer cells
The bonds in polysaccharides are called…
Glycosidic bonds
A polysaccharide is formed from…
Monosaccharides
Starch is formed from…
Long chains of alpha glucose
Glycogen is used for…
Energy storage molecules in animals
Cellulose is made from…
Condensation reactions of beta glucose molecules
Properties of polysaccharides are…
Insoluble in water, long chain molecules, not sweet tasting
Starch is stored as…
Grains in chloroplasts
Glycogen is found in…
Liver and muscle cells
What is the main difference between active transport and facilitated diffusion?
Active transport requires ATP, whereas facilitated diffusion does not because it is passive.
What is the water potential of water?
0 kPa (kilopascals)
What is a glycolipid?
A lipid with a carbohydrate molecule attached
Explain why alcohol is used in antiseptic wipes
Alcohol disrupts and dissolves the bacteria phospholipid bilayer due to the non-polar nature, killing the organelles in the cell
State four functions of membranes within cells
Controls what enters and leaves the partially permeable plasma membrane.
Site of chemical reactions.
Compartmentalisation.
Forms vesicles.
Acts as a barrier between membrane contents and rest of organelle.
Give an example of a conjugated protein
Haemoglobin, catalase
Explain how a positive result is formed in Benedict’s test
Reducing sugar reacts with blue Cu2+ to make brick red Cu+ precipitate
Based on the arrangement of cellulose molecules, explain why cell walls provide strength and support to plant cells
Cellulose molecules form hydrogen bonds with each other to make microfibrils. Microfibrils join together to form macrofibrils which join further to form fibres. These fibres are insoluble and tough.
State the bonds involved in the tertiary structure of a protein
Ionic
Disulphide bridges between cysteine (covalent)
Hydrogen bonds
Hydrophobic interactions
Describe the structure of amylopectin, including the bonds involved and the shape
Amylopectin is a polysaccharide with a branched structure. Includes 1-4 and 1-6 glycosidic bonds.
