4.0 DIGESTIVE ENZYMES

   These are organic catalyst which is usually proteinous in the nature, which speed up the rate of chemical activities in the living cell but not speed up in the process.

   TYPES OF ENZYMES
   (I) Intracellular: Enzymes found inside the body of an organism. e.g respiratory
   (II) Extracellular: Enzymes found outside the cell.

4.1 CHARACTERISTICS OF ENZYMES

   1. They are specific in action
   2. They are proteineous in nature
   3. They speed up the rate of chemical reactions
   4. They are affected by temperature
   5. They have active sites
   6. They are not use or change during chemical reactions
   7. Action of enzymes are reversible

4.2 ENZYMES SOURCES AND LOCATION

   i. Ptylin

   (Source: Salivery gland / Loacation: Mouth)

   ii. Renin , Pepsin

   (Source: Gastric gland / Location: Stomach)

   iii. Plancentric Lipase

   (Source: Pancrease / Location: Duodenum)

   iv. Trypsin , Anylase

   (Source: Pancrease / Location: Duodenum)

   v. Erepsin

   (Source: Succus enticus / Location: Small intestine)


4.3 MODE OF NUTRITION AND THEIR TYPES

   Plants are able to manufactured their own food in a process called photosynthesis, while animals depend on already manufactured food.

   (i) Autotrophic Nutritions: Plant are able to manufactured their own food through photosynthesis, or some bacteria make use of chemical in synthesis in simple inorganic substance. e.g Holophytic and Chemosynthetic nutrition. Types of autotrophic are;

   * Holophytic: is the type of nutrition in which green plant containing chlorophyl use carbondioxide,water in presence of sunlight.

   * Chemosynthetic: is the type of nutrition in which some bacteria are able to synthesize simple inorganic substance from carbondioxide,water,oxygen.

   (ii) Heterotrophic Nutritions: This is a nutrition in which organism are enable to manufactured their own food but depends on already manufactured food. e.g Green plant. Type of heterotrophic are;

   * Holozoic: is the type of nutrition in animal in which they obtained their own food by ingesting, digesting, assimilating the food into their body cells. e,g (Carnivore, Herbivore, Omnivore, Scavages)

   * Parasitic: is the type of nutrition in which the parasite live in or on their host to obtain nutrient, food, protein at the expense of the host. e.g (Tapeworms)

   * Saprophytic: is the type of nutrition in which the saprophytic feeds on dead and decay organic material by secreting enzymes on substance thereby digesting it.

   * Symbotic: is the type of nutrition in which two organism of difference species called symbotic live together and derive nutrition or food from each other.

4.4 ECOSYSTEM

   This is the functioning unit in nature which made up biotic (Plant and Animal) and their non-living thing environment. It can also be the interaction between living and non-living things in their environment.

   ECOLOGY

   This is the study of plant and animal in relations to their environment. its derived from a greek word "Okios" which means "home or dwelling place"

4.5 BRANCHES OF ECOLOGY

   (i) Autecology: It is concerned with the study of an individual organism and its environment
   (ii) Synecology: It is the study of the inter relationship between two groups of organism or species of organism living together in area.

4.6 ECOLOGICAL CONCEPT

   1. Environment: it includes external and internal factors, living and non-living factors which affect an organism

   2. Biosphere: it is the ozone layer occupied by living organism. It can be found on land, soil, water, air where they provide habitat.

   3. Lithosphere: It is the solid portion of the earth which is made up of rocks and animals. it represent 30% of the earth surface which made up of gravel, sand & soil.

   4. Hydrosphere: Is the liquid or aquatic part of the earth or living word convert about (70%) of the earth crust

   5. Atmosphere: It is the gaseous portion of the earth. e.g Nitrogen (78%), Oxygen (21%), Carbondioxide (0.02%) and Rare gases (0.97%).

   6. Habitat: It is the natural home of an organism or area occupied by a community.

   7. Ecological Niche: It is the specific portion of a particular species or organism carterpiller and an aplud which live on the same plant

   8. Population: It is the total number of organism of the same species living together in a given area.

4.7 COMPONENT OF ECOSYSTEM

   The green plant manufactured their own food by making use of carbon(iv)oxide and chlorophyll in the presence of sunlight produce carbohydrate in a process called photosynthesis. 

   A. Biotic Component (Living things)

   * Producer: are autotrophs which manufacture their own food from simple inorganic materials

   * Consumer: are heterotroph which can not manufacture their own food but depend on already manufactre food.

   * Decomposer: are bacteria and some are fungi which break down dead organic materials.

   B. Abiotic Component (Non-living things)

   * Climatic factor like temperature, wind, humidity

   * Inorganic materials and nutrient

   * Edaphic factor like soil, rocks
   
   * Other factors like dust, storm, fire



[1] What is Enzymes ?
[2] List and explain 2 types of enzymes
[3] Give the characteristics of enzymes
[4] What is ecosystem ?
[5] What is ecology ?
[6] List and explain the ecology concept you know
[7] List and explain the two component of ecosystem
[8] Differenciate between autotrophic and heterotrophic nutrition
[9] List The Sources and location of enzymes you know
[10] What is photosynthesis ?