Life Processes- Respiration Blog 1

Welcome back students! HOPE YOU ARE ALL DOING WELL!   😊

Look at the answers to yesterday’s assignment.

Q1) Why do herbivorous animals have a larger small intestine?

A1) Herbivorous animals have a longer small intestine to allow cellulose to be digested. Cellulose is difficult to digest.

Q2) list differences between the two protein digesting enzymes-

Trypsin and pepsin

A2) Trypsin – it’s a protein digesting enzyme which works in alkaline medium and is secreted by pancreas

and pepsin – its a protein digesting enzyme which works in acidic medium and is secreted by stomach

Q3) How are villi of small intestine different from those of large intestine?

A3) Villi of small intestine absorbs digested food and is passed into blood to be transported to all parts of the body.

Villi of large intestine absorbs water from undigested food, which is then excreted through anus.

DEAR STUDENTS, WE HAVE COMPLETED THE PROCESS OF NUTRITION AND WILL BE BEGIN WITH SECOND IMPORTANT LIFE PROCESS THAT IS RESPIRATION.

  

LIFE PROCESSES- RESPIRATION

By the end of today’s class, the student will be able to

     
     1)      Define respiration

     2)      Distinguish between breathing and respiration

     3)      Know the two types of respiration- aerobic and anaerobic

     4)      Draw a neat labelled diagram of human respiratory system and study its parts.

     5)      Study the mechanism of breathing.

PLEASE COPY EVERYTHING IN YOUR BIOLOGY NOTEBOOK EXCEPT THAT WHICH IS WRITTEN IN RED. KEEP YOUR NCERT WITH YOU FOR ANY REFERENCE.

RESPIRATION

It is defined as a biochemical process that involves taking in oxygen, utilising it to break down food, to release energy and gives out carbon dioxide.

( COPY THE ABOVE TABLE)

Read page no 101 and 102 of your text book.

The food material taken in during the process of nutrition is used in cells to provide energy for various life processes. Diverse organisms do this in different ways- some use oxygen to break glucose completely into carbon dioxide and water whereas some use other pathways that do not involve oxygen.

STEPS OF BREAK DOWN OF GLUCOSE

STEP 1:  The first step is the break down of glucose, six carbon molecule into a three carbon molecule called pyruvate. This take place in the cytoplasm.

STEP 2: (In absence of Oxygen) This pyruvate is converted into ethanol and carbon dioxide. This process take place in yeast during fermentation. This is called as anaerobic respiration.

STEP 3:  (In presence of Oxygen) This pyruvate is converted into carbon dioxide, water and energy. This process take place in mitochondria. This is called as Aerobic respiration.

STEP 4: (In lack of Oxygen) This pyruvate is converted into lactic acid and energy. This process take place in our muscle cells. This lactic acid which is also three-carbon molecules. This build-up of lactic acid in our muscle during sudden activity causes cramps.

TYPES OF RESPIRATION   ( COPY THE  TABLE)

                       BREAK DOWN OF GLUCOSE BY VARIOUS PATHWAYS

THE FOLLOWING FLOW CHART SHOWS AEROBIC AND ANAEROBIC RESPIRATION.

THE MIDDLE ONE SHOWS AEROBIC RESPIRATION WHERE GLUCOSE IS FIRST OXIDISED TO A MOLECULE CALLED PYRUVATE. THIS PROCESS OCCURS IN CYTOPLASM. THIS STEP DOES NOT REQUIRE OXYGEN AND IS CALLED GLYCOLYSIS. PYRUVATE MOLECULE ENTERS MITOCHONDRIA AND BREAKS DOWN INTO CARBON DIOXIDE, WATER AND ENERGY IN THE FORM OF ATP.

THE FIRST PATHWAY IS ANAEROBIC RESPIRATION. IN THIS ALSO GLUCOSE IS FIRST OXIDISED TO A MOLECULE CALLED PYRUVATE, PYRUVATE MOLECULE THEN BREAKS DOWN INTO ETHANOL(ALCOHOL) CARBON DIOXIDE AND ENERGY IN THE FORM OF ATP . THIS RESPIRATION OCCURS IN YEAST.

THE THIRD PATHWAY IS AGAIN ANAEROBIC RESPIRATION. IN THIS ALSO GLUCOSE IS FIRST OXIDISED TO A MOLECULE CALLED PYRUVATE, PYRUVATE MOLECULE THEN BREAKS DOWN INTO LACTIC ACID AND ENERGY IN THE FORM OF ATP . THIS RESPIRATION OCCURS IN HUMAN MUSCLE CELLS ONLY DURING VIGOROUS EXERCISE,WHEN THERE IS A DEFICIENCY OF OXYGEN.

THE LACTIC ACID PRODUCED IN THIS WAY IN MUSCLES CAUSES MUSCULAR CRAMPS.

The energy released during cellular respiration is immediately used to synthesise a molecule called ATP which is used as fuel for doing activities in the cell. ATP is broken down giving rise to a fixed amount of energy which can drive the ENDOTHERMIC REACTIONS taking place in the cell.

THIS FLOW CHART IS NOT TO BE DRAWN. INSTEAD COPY THE FLOW CHART FROM NCERT PAGE 102 FIG 6.8.   

RESPIRATION IN ANIMALS

1. In simple unicellular animals like amoeba, respiration takes place by the simple diffusion of gases through the cell membrane.

2. The animals like earthworm which live in the soil use their moist skin to absorb oxygen and remove carbon dioxide.

3. The aquatic animals like fish, prawns have gills which absorb oxygen in dissolved in water.

4. In the insect like grasshoppper and cockroach have tiny holes called spiracles and the air tubes called tracheae are the respiratory organs.

Read Page 102-103 of text book NCERT

                                             Breathing Mechanism in Human

THIS PICTURE EXPLAINS THE MECHANISM OF BREATHING. NOW COPY THE TABLE GIVEN BELOW.

Draw the well labeled diagram fig 6.9 page 104

Respiration in Human
1. In human being, air is taken into the body through the nostrils. The air passing through the nostrils is filtered by fine hairs that line the passage.

2. The passage is also lined with mucus which helps in this process.

3. The air passes through the throat and into the lungs.

4. Rings of cartilage are present in the throat. These ensure that the air-passage does not collapse.

5. In the lungs, the passage divides into smaller and smaller tubes which finally terminates in balloon like structure which are called Alveoli.

6. The alveoli provide a surface where the exchange of gases take place.

7. The walls of the alveoli contain an extensive network of blood vessel 

ASSIGNMENT FOR TODAY

Q1) HOW IS SMALL INTESTINE DESIGNED TO ABSORB DIGESTED FOOD?

Q2) NAME A DIGESTIVE GLAND WHICH CONTAINS NO ENZYMES.

Q3) READ PAGE 101, AND ALSO ACTIVITIES 6.4 AND 6.5

Q4) WHAT HAPPENS WHEN WE EXERCISE VIGOROUSLY?

STUDENTS PLEASE COMPLETE YOUR WORK TILL THIS POINT. 

TAKE CARE 😇