Cell Structures and functions and its related features

 Cell structures

 

Cell structure	Features(characteristics)	Functions
Nucleus	Contain DNA, the genetic material, carries the genetic information	Controls the activities of the cell
	There are pores in the nuclear membrane	Allow the exchange of materials between the nucleus and the cytoplasm
	-          Spherical -          Bounded by double membrane(nuclear membrane)	---
Cytoplasm	-          Jelly-like fluid -          Contains enzymes -          Mainly made up of water and proteins	Holds many organelles
		Site for many chemical reactions
		Allows the movement and transport of materials inside the cell
Cell membrane	-          Is a membrane, mainly made up of phospholipid	Encloses the cell and separates the cell contents from the outside
	-          Differentially permeable (only allow certain substances to pass through) -          Made of up specific proteins	Controls the movement of substances into and out of the cells
	-          Flexible	----
Cell wall	-          Fully permeable	Allow water and dissolved substance to pass through
	-          Thick, rigid outermost layer -          Mainly made up of cellulose	Protect, supports and give shape to the plant cells
Endoplasmic reticulum(ER)	-          Continuous with outer nuclear membrane and extends throughout the cytoplasm -          Two types	Efficiently transport of materials withing the cell
Rough endoplasmic reticulum	-          With ribosomes attached on the surface	Site of synthesis of protein
Smooth endoplasmic reticulum	-          Without ribosomes	Site of synthesis of lipids
Ribosomes	-          Small particles, -          No membrane -          Some are lying free in the cytoplasm	Involved in the synthesis of proteins
Mitochondrion	-          With related enzymes	Main site of respiration -          Converts chemical energy in food into energy that the cell use
	-          Bounded by double membrane -          Inner membrane is highly folded	----
Chloroplast	-          Contain chlorophyll (a green pigment)	Carry out photosynthesis -          Captures light energy and converts into chemical energy in food
	-          Present in green plant cells -          Bounded by a double membrane, with a network of membrane inside -          Starch grains are often present	----
Vacuole	-          The membrane is flexible	When become turgid (the central vacuole is full of water), provide support to the plant
	-          Fluid-like sac surrounded by a single membrane -          Contains water and dissolved substances, such as glucose, pigments and wastes	----

 

 

Test yourself

1. List the names of all cell structures that need to be known within the scope of the DSE curriculum.

2. What are the functions and related characteristics (or structures) of the following cellular structures?

(1) cell wall

(2) cell membrane

(3) Cytoplasm

(4) rough endoplasmic reticulum

(5) smooth endoplasmic reticulum

(6) Endoplasmic reticulum

(7) Ribosomes

(8) Vacuole

(9) Chloroplasts

(10) nucleus

3. Which of the above structures are double-layer membranes?

4. Which of the above structures only exist in plant cells, but not in animal cells?

5. Which types of cells in the human body contain more mitochondria? What are the common needs of these types of cells?

6. Which types of cells in the human body contain more rough endoplasmic reticulum? What are the common functions of these types of cells?

7. What is the main component of plant cell wall?

8. Which components on the cell membrane can control the movement of substances into and out of the cell membrane?

9. Which of the above cell structures can only be observed under an optical microscope?

10. Which cells in the human body do not have nuclei?

11. Which cells in the human body do not have mitochondria? What is the significance of it?

12. Which living cells in plants do not have chloroplasts?

13. Which of the above structures do prokaryotic cells (such as bacteria, etc.) lack?

 

Advanced Questions:

1. Viruses must enter cells to replicate themselves, but some viruses cannot enter human cells. what is the reason?

2. The functions of the rough endoplasmic reticulum and the free ribosomes in the cytoplasm are the same. What is that? But where the product goes is a little different. What's the difference?

3. How do substances of different properties move in and out of cells?

 

Structures of an animal and a plant cell

Structures of animal cell

重要提示:

1. 以下的內容並不是所有需要學習的內容，祇是重點!

2. 請務必理解好每個構造(structure)，其特徵(characteristic)與功能(function)的關係。那些特徵與功能的關係是非常密切的，你祇要背誦任何一項，另一項應該可推論出來的。

3. 紅色標示的是相對更重要的字眼，不要遺漏! 但作答時也不要祇作答紅色標示的字，那不一定可以得到任何分數。

Relationships among the structures, characteristics and functions

Structures	Characteristics	Functions
Cell membrane	Flexible Differentially permeable	Controls the movement of substances in and out of the cell
Cytoplasm	Jelly-like fluid Contain many enzymes	Holds many organelles Site for many chemical reactions
Nucleus	Contain DNA which carries genetic information	Controls activities of the cell
Mitochondrion	Contains many enzymes for respiration	Site for energy-releasing
Rough endoplasmic reticulum	Network of interconnected membrane-bounded sacs With ribosomes attached on the surfaces	Transportation of materials in the cell Involved in the synthesis of protein
Smooth endoplasmic reticulum	Network of interconnected membrane-bounded sacs ---	Transportation of materials in the cell Involved in the synthesis of lipid
Vacuole	Contains water and dissolved substances	Storage of some dissolved substances
Ribosome	----	Responsible for synthesis of protein

Structures of Plant cells

重要提示:

1. 以下列出的祇是植物細胞較動物細胞多了的構造。所有動物細胞具有的構造，植物細胞有擁有。

Relationships among the structures, characteristics and functions of a plant cell.

Structures	Characteristics	Functions
Cell wall	Rigid, thick, mainly made up of cellulose Fully permeable	Protect, supports and give shape to the plant cells. Allow water and all dissolved substances to pass through
Large vacuole	Contains water and dissolved substances such as glucose, pigment and waste	Storage of dissolved substance
Chloroplast	Contains a green pigment chlorophyll	Absorb light energy for photosynthesis

suggested answer (2018-06-06)

Biology Test

Date:2018-06-06

Class: ___________(    )             Name: ____________    Mark: _________

Section I: 30%

1. List the functions of different types of teeth:

  (i) incisor: biting and cutting the food

   (ii) canine:  tearing flesh

   (iii) molar:  crushing and grinding the food

2. Finish the following table to show the chemical digestion:

Digestive glands	Digestive juices	Enzymes involved	Site of Action	Functions(actions) of the enzyme(s)
Saliva	Saliva	Salivary amylase	Mouth cavity	Starch - > maltose
Gastric gland	Gastric juice	pepsin	Stomach	Protein ->peptides
Pancreas	Pancreatic juice	Pancreatic amylase Pancreatic proteases lipase	Duodenum	Starch -> maltose Protein->peptides ->amino acid
Intestinal glands	Intestinal  juice	Carbohydrases proteases	ileum	Disaccharides -> monosachharides

Section II: 70%

1. Fill in the blanks to show the relationship between the features and functions:

Structures	Related features	Functions
Enamel	Hard / made up of calcium salts	Protect the tooth from wearing
Pulp cavity	Contain blood vessels	Provide nutrient and oxygen to the tooth
Stomach	Contain hydrochloric acid	Kill bacteria in the food
Wall of alimentary canal	Contain mucus	Prevent the wall from digestion by proteases

2. List the name(s) of the digestive juices related to the digestion of starch.

Saliva, pancreatic juice

3. List the name(s) of the digestive glands related to the digestion of protein.

Gastric gland, pancreas, intestinal gland

4. List the site(s) in the alimentary canal where proteins are digested

Stomach, duodenum, ileum

5. List the site(s) in the alimentary canal where carbohydrates are digested

Mouth cavity, duodenum                                                                                                 

6. List the site in the alimentary canal where protein begin to be digested

stomach 

7. List the site in the alimentary canal where starch begin to be digested

Mouth cavity

8. List the site in the alimentary canal where lipids begin to be digested

Duodenum

9. State the function of bile salt to digestion:  

Emulsify the large oil droplets to  smaller ones to increase the surface areas for the action of lipase

10  A cell belongs to a living thing, should have all living characteristics. Fill in the         blanks below to show the relationship between the structures and the living      characteristics.

Structures	Functions	Related living characteristics
Mitochondrion	Break down food to provide energy	Respiration
Chloroplast	Carry out photosynthesis	Nutrition
Vacuole	Collect metabolic wastes in plant cells	excretion

11. Explain the reason why taking in too much rice will lead to overweight.

Rice contain starch. Starch is carbohydrate. If taking in too much carbohydrate, the excessive carbohydrate will change into lipid. The lipid will be stored under the skin to make us overweight.

12. How to prove the presence of vitamin C in orange juice?

  Add the orange juice solution into the DCPIP with fixed volume, if the colour of the DCPIP change from deep blue to orange the orange juice solution contains vitamin C.

13. State the effect on digestion if the gall bladder is cut.

   Bile is stored in the gall gladder, if the gall bladder is cut, less bile will be secreted to the duodenum. As a result, less lipid will be emulsified. The digestion of lipid will become less.

14. List any 5 types of substances that are present in the faeces.

   Unabsorbed substances, undigested substances, dietary fibre, mucus, bacteria from the gut, digestive enzymes, water, bile pigment, cells from the gut wall, remaining hydrochloric acid, remaining hydrogencarbonate….

   Any 5