cell structure pg 43-46

Question 1

protein synthesis and secretion

Answer 1

polypeptide chains are synthesized in the ribosomes and folded in the endoplasmic reticulum. transport vesicles carrying substances like proteins and lipids made by the ER is pinched off from the ER. these transport vesicles fuse with golgi apparatus and releases their substance there. the substances are then chemically modified and packaged in the golgi apparatus. secretory vesicles move towards and fuse with the cell membrane, releasing the substances outside the cell by exocytosis

Question 2

formation of lysosome

Answer 2

enzyme contents are synthesised in the rough ER and transported via transport vesicles to the golgi apparatus for further processing.
a vesicle containing the processed enzymes buds off from the golgi apparatus forming lysosome
enzymes have to be kept away from the rest of the cell or else they would destroy the cell.

Question 3

adaptation and function of root hair cell

Answer 3

long narrow extension

increase surface area to volume ratio for faster rate of diffusion of mineral salts by osmosis

Question 4

Adaptation and structure of red blood cell

Answer 4

Presence of haemoglobin in cytoplasm as haemoglobin combines reversible with oxygen

Absence of nucleus to allow more haemoglobin to be packed to bind more oxygen

Biconcave shape to increase surface area to volume ratio for faster rate of diffusion of oxygen and carbon dioxide

Question 5

Adaptation and structure of muscle cell

Answer 5

Elongated cylindrical shape, contains many nuclei and mitochondria. Has numerous mitochondria to provide energy for the contraction of the muscle cell

Question 6

Level of complexity of body

Answer 6

Macromolecules- haemoglobin and chlorophyll (large complex molecule made up of small monomers linked together with relatively large molecular mass)

Organelle- chloroplast and mitochondria (differentiated structure within the cell which performs a specific function)

Cell- red blood cell, white blood cell( the building blocks of life, simplest units of life containing all characteristics of life)

Tissue- adipose tissue, muscle (a group of similar cells work together to perform a specific function)

Organ- heart, stomach (structure made up of different tissues working together to perform a specific function)

Organ system- digestive ( several organs working together for a common purpose)