aqa biology paper 1 Exam
Questions and Answers 100%
PASS
Figure 1 shows the structure of a fatty acid molecule and the structure of a
glycerol molecule.
On Figure 1, draw a circle around the part of the fatty acid molecule and the
part of the glycerol molecule that is removed to form a bond in a triglyceride
molecule.
Name the bond formed between a fatty acid and glycerol in a triglyceride
molecule.
Name the reaction involved in forming a bond between a fatty acid and
glycerol in a triglyceride molecule.—ANSWER-1. Circle(s)/shape(s) drawn
around H in one of the HO groups of the glycerol and the OH group of the
fatty acid;
,2. Ester (bond);
3. Condensation(reaction);
Name the fatty acid shown in Table 1 that is a saturated fatty acid.—
ANSWER-stearic acid
The melting point is the temperature at which a solid changes state to be a
liquid.
Use Table 1 to describe the relationship between fatty acid structure and
fatty acid melting point.—ANSWER-As (number of C) double bonds
increases, melting point decreases or As saturation increases, melting point
increases;
The ratio of saturated to unsaturated fatty acids in a cell-surface membrane
determines the extent of the membrane's fluidity.
Scientists provided a cell culture of mouse phagocytes with liquid broth rich
in unsaturated fatty acids.
The scientists observed:
· an increase in the proportion of phospholipids in the phagocytes containing
unsaturated fatty acids
· more phagocytosis.
© 2026 Copyright. All Rights Reserved. This document is
protected by copyright law, Copyrighted By Katelyn Whitman
, Suggest and explain why there was more phagocytosis—ANSWER-1. More
unsaturated fatty acids increases fluidity (in (cell-surface membrane);
2. (Making cell-surface) membrane more fluid/ flexible;
Easyto engulf and easier for phagosomes to form
Describe the processes of facilitated diffusion and active transport.
[3 marks]—ANSWER-1. (Movement of) polar/charged/non lipid soluble
molecules;
2. (Facilitated diffusion) movement down a concentration gradient via
carrier/channel protein;
(Active transport) movement against a concentration gradient via carrier
protein using ATP;
What are microvilli?—ANSWER-Highly) folded cell(-surface) membrane;
Vitamin A is a fat-soluble substance.
Micelles are involved in the process of vitamin A absorption.
Describe the process of vitamin A absorption into cells lining the ileum—
ANSWER-1. Combine/mix/join with bile salts;
2. Make (more) soluble (in water);
3. Micelles Transport to cells/lining/Maintain high(er) concentration at cell(-
surface membrane);
Questions and Answers 100%
PASS
Figure 1 shows the structure of a fatty acid molecule and the structure of a
glycerol molecule.
On Figure 1, draw a circle around the part of the fatty acid molecule and the
part of the glycerol molecule that is removed to form a bond in a triglyceride
molecule.
Name the bond formed between a fatty acid and glycerol in a triglyceride
molecule.
Name the reaction involved in forming a bond between a fatty acid and
glycerol in a triglyceride molecule.—ANSWER-1. Circle(s)/shape(s) drawn
around H in one of the HO groups of the glycerol and the OH group of the
fatty acid;
,2. Ester (bond);
3. Condensation(reaction);
Name the fatty acid shown in Table 1 that is a saturated fatty acid.—
ANSWER-stearic acid
The melting point is the temperature at which a solid changes state to be a
liquid.
Use Table 1 to describe the relationship between fatty acid structure and
fatty acid melting point.—ANSWER-As (number of C) double bonds
increases, melting point decreases or As saturation increases, melting point
increases;
The ratio of saturated to unsaturated fatty acids in a cell-surface membrane
determines the extent of the membrane's fluidity.
Scientists provided a cell culture of mouse phagocytes with liquid broth rich
in unsaturated fatty acids.
The scientists observed:
· an increase in the proportion of phospholipids in the phagocytes containing
unsaturated fatty acids
· more phagocytosis.
© 2026 Copyright. All Rights Reserved. This document is
protected by copyright law, Copyrighted By Katelyn Whitman
, Suggest and explain why there was more phagocytosis—ANSWER-1. More
unsaturated fatty acids increases fluidity (in (cell-surface membrane);
2. (Making cell-surface) membrane more fluid/ flexible;
Easyto engulf and easier for phagosomes to form
Describe the processes of facilitated diffusion and active transport.
[3 marks]—ANSWER-1. (Movement of) polar/charged/non lipid soluble
molecules;
2. (Facilitated diffusion) movement down a concentration gradient via
carrier/channel protein;
(Active transport) movement against a concentration gradient via carrier
protein using ATP;
What are microvilli?—ANSWER-Highly) folded cell(-surface) membrane;
Vitamin A is a fat-soluble substance.
Micelles are involved in the process of vitamin A absorption.
Describe the process of vitamin A absorption into cells lining the ileum—
ANSWER-1. Combine/mix/join with bile salts;
2. Make (more) soluble (in water);
3. Micelles Transport to cells/lining/Maintain high(er) concentration at cell(-
surface membrane);
