cell structure and function

Question 1

core functions of human cells

Answer 1

• cell division
• DNA replication and protein synthesis
• cell respiration
• cell migration
• cellular transport

Question 2

prokaryotic cells

Answer 2

• single closed compartment
• no defined nucleus

Question 3

eukaryotic cells

Answer 3

• has membrane enclosed organelles
• contains defined membrane bound nucleus

Question 4

plasma membrane

Answer 4

• dynamic selective barrier
• phospholipid bilyaer
• cell membrane can be repaired if damaged

Question 5

cytoskeleton

Answer 5

• gives shape, makes it dynamic
• made of fillaments

Question 6

microfilaments

Answer 6

• made of actin
• contractile forces and movement
• moves due to actin polarisation and depolarisation

Question 7

intermediate filaments

Answer 7

• strengthens
• gives shape
• nucleus anchor

Question 8

microtubules

Answer 8

• hollow tubes and spindle
• used for chromosome division

Question 9

protein folding

Answer 9

• change in amino acid sequence means that the polypeptides will be misfolded
• ubiquitin tag added to misfolded protein so it can be degraded

Question 10

mitochondria

Answer 10

• harness energy comes from the mitochondria
• energy in the form of ATP use to power protein synthesis, transport of molecules, muscle contraction, cellular movement

Question 11

cell division stages

Answer 11

• G1 and s - dna replication
• G2 - check DNA is correct after replication
• m - mitosis
• G1-S-G2 - interphase

Question 12

stages in mitosis

Answer 12

• prophase (spindles emerge, condense)
• prometaphase (nuclear envelop broken down, kinetochores at centromere)
• metaphase (spindles line up)
• anaphase (sister chromatids split)
• telophase (opposite side of cell)
• cytokinesis (division of the cells)

Question 13

protein synthesis stage

Answer 13

1. transcription of mRNA
2. mRNA leaves nucleus and docked to ribosomes and translated into polypeptides
3. polypeptides are folded in the cytoplasm - more to ER
4. move from ER to Golgi and are modified
5. transported via vesicles and transported to their desired location