Paper 1 bio total last Flashcards
(33 cards)
What are the monomers of carbohydrates?
Monosaccharides such as glucose.
Describe the test for reducing sugars.
Add Benedict’s reagent and heat. A positive result is a brick-red precipitate.
What bond forms between monosaccharides?
Glycosidic bond.
Describe the structure and function of starch.
Made of amylose and amylopectin; stores glucose in plants.
What is the difference between saturated and unsaturated fatty acids?
Saturated fatty acids have no double bonds; unsaturated have at least one double bond.
Describe the emulsion test for lipids.
Mix with ethanol and water; a white emulsion indicates lipids.
What is the role of enzymes?
Biological catalysts that speed up reactions by lowering activation energy.
How does temperature affect enzyme activity?
Increases rate up to optimum, then denatures enzyme if too high.
What organelles are found in eukaryotic cells?
Nucleus, mitochondria, rough and smooth ER, Golgi apparatus, lysosomes, ribosomes, cell membrane.
What is the function of the Golgi apparatus?
Modifies and packages proteins and lipids.
What is the function of lysosomes?
Contain digestive enzymes to break down waste or pathogens.
How are prokaryotic cells different from eukaryotic?
Prokaryotes lack membrane-bound organelles and have smaller ribosomes.
What is the function of the plasma membrane?
Controls the movement of substances in and out of cells.
Describe the fluid mosaic model.
Phospholipid bilayer with embedded proteins; fluid due to lipid movement.
What is diffusion?
Net movement of particles from high to low concentration.
What is facilitated diffusion?
Diffusion through protein channels or carriers, no energy required.
How does active transport differ from diffusion?
Active transport uses energy (ATP) to move substances against their concentration gradient.
What is osmosis?
The diffusion of water from high to low water potential through a partially permeable membrane.
How do insects exchange gases?
Through a tracheal system of tubes directly connected to cells.
How do fish maintain efficient gas exchange?
Using counter-current flow across gill lamellae.
How are alveoli adapted for gas exchange?
Large surface area, thin walls, good blood supply, moist lining.
What is the role of haemoglobin?
Binds oxygen in the lungs and releases it in tissues.
How is tissue fluid formed?
High hydrostatic pressure forces plasma out of capillaries at the arterial end.
