Zadanie 9, Paper 2, maj 2026, TZ2, Biologia IB HL
Wzorowane na: Biology HL Paper 2, May 2026, TZ2, pytanie 9. Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Zadanie
Polecenie
Glucose connects molecular structure, energy release and physiological regulation.
(a) Distinguish alpha-glucose and beta-glucose in structure and biological role.
(b) Explain the regulation that prevents large sustained changes in human blood glucose concentration.
(c) Outline the conversion of glucose into pyruvate during glycolysis.
Korepetytor AI
Nie wiesz, jak ruszyć? Korepetytor zna to zadanie i poprowadzi Cię krok po kroku, bez gotowca.
3 rozmowy · bez karty · Zaloguj się
Sprawdź się
Odpowiedz i oceń, jak poszło. Klucz odsłoń dopiero, gdy masz swoją odpowiedź.
Jak poszło Ci z tym zadaniem?
Wybierz ocenę: zapamięta ją ta przeglądarka, a z darmowym kontem zobaczysz ją na każdym urządzeniu.
Pokaż rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
(a) In the usual Haworth orientation, alpha-glucose has its carbon-1 hydroxyl below the ring. ✔
Beta-glucose has the corresponding hydroxyl above the ring. ✔
The C1 and C4 hydroxyls are on the same side in alpha-glucose but opposite sides in beta-glucose. ✔
Alpha-glucose units link into the polymers starch and glycogen. ✔
Beta-glucose units link into cellulose chains. ✔
Alpha-glucose and its storage polymers provide a readily mobilized energy supply. ✔
Cellulose provides tensile strength to plant cell walls. ✔
(b) Homeostasis regulates the internal environment. ✔
Negative feedback opposes departures from the regulated level. ✔
The pancreas produces insulin OR glucagon. ✔
Insulin OR glucagon travels in blood plasma. ✔
Insulin OR glucagon acts on target cells. ✔
The pancreas OR hypothalamus monitors blood glucose. ✔
High glucose stimulates insulin release. ✔
Pancreatic beta cells are the source of insulin. ✔
Insulin promotes glucose uptake into responsive cells. ✔
It promotes conversion of glucose to glycogen in liver and muscle. ✔
Low glucose stimulates glucagon release. ✔
Pancreatic alpha cells produce glucagon. ✔
Glucagon stimulates liver glycogen breakdown. ✔
It promotes release of glucose into the blood. ✔
(c) Glucose is phosphorylated early in the pathway. ✔
The six-carbon intermediate is split into two three-carbon phosphorylated sugars. ✔
The three-carbon intermediates are oxidized. ✔
NAD is reduced. ✔
ATP is produced, OR phosphate is transferred to ADP from a three-carbon intermediate. ✔
Successive steps use different enzyme catalysts. ✔
Schemat punktowania
(a) Award up to 3 structural/polymer-linkage points and up to 2 functional points, maximum 4 overall. Polymer answers must convey repeated glucose units; accept correct labelled structures. (b) Award any 7 points, maximum 7. (c) Award any 4 points, maximum 4. Quality: award 1 additional mark for an overall response across all parts that is readily understandable, concise and largely free of repetition and irrelevant material. Assess this separately from content. Maximum 16 marks overall.