CBSE Class 10 Biology

Introduction to Acids, Bases and Salts
Classification of matter


On the basis of
a) composition – elements, compounds and mixtures
b) state – solids, liquids and gases
c) solubility – suspensions, colloids and solutions

Types of mixtures – homogeneous and heterogeneous
Types of compounds – covalent and ionic

To know more about Classification of Matter,

What Is an Acid and a Base?
Ionisable and non-ionisable compounds
An ionisable compound when dissolved in water or in its molten state, dissociates into ions almost entirely. Example: NaCl, HCl, KOH, etc.
A non-ionisable compound does not dissociate into ions when dissolved in water or in its molten state. Example: glucose, acetone, etc.


Physical test
Given are two possible physical tests to identify an acid or a base.

a. Taste
An acid tastes sour whereas a base tastes bitter.
The method of taste is not advised as an acid or a base could be contaminated or corrosive.

b. Effect on indicators by acids and bases
An indicator is a chemical substance which shows a change in its physical properties, mainly colour or odour when brought in contact with an acid or a base.
Below mentioned are commonly used indicators and the different colours they exhibit:

🌳Revision Notes on Reproduction in Organisms🐾

Fertilization:
(a) The process of fusion of male and female gamete is called fertilization or syngamy.

(b) The female gamete undergoes development to form new organism without fertilization. This phenomenon is called parthenogenesis. It is a modification of sexual reproduction.

(c) Gametic fusion taking place outside the body i.e. water is called external fertilization.

(d) There must be synchrony of gamete release. Large number of gametes is released to enhance the chance of fertilization.

(e) A major disadvantage is that the offsprings are extremely vulnerable to predators.

(f) Fertilization takes place inside the body is called internal fertilization.

Zygote:
(a) Formation of zygote after fertilization is found in all sexually reproducing organisms.

(b) In case of external fertilization, zygote is formed usually in water.

(c) In case of internal fertilization, zygote is formed inside the body of the organism.

(d) Zygote of fungi and algae develops a thick wall that is resistant to desiccation and damage.

(e) Organism with haplontic life cycle, zygote undergoes meiosis to produce haploid spores.

Embryogenesis:
(a) The process of development of zygote into an embryo is called embryogenesis.

(b) Zygote undergoes cell division (mitosis) and cell differentiation.

(c) Oviparous are the animals which lay eggs and development takes place inside egg.

(d) Viviparous animals give birth to the young ones. The development takes place inside the body of the female.

(e) In plants:

(i) Zygote developed into embryo.

(ii) Ovule developed into seed

(iii) Integument of the ovule developed into seed coat.

(iv) Ovary developed into fruit.

(v) Ovary wall developed into pericarp.

1: Bauxite is the ore of
Ans. Aluminium

2 . The chemical formula for Bauxite is
Ans. Al2 O3 . 2H2O

3. Corundum and Crylolite are also ore of
Ans. Aluminium

4. The chemical formula for Corundum is
Ans. Al2O3

5. The chemical formula for Crylolite is
Ans. Na3 AlF6

6. Neutron is discovered by
Ans. Chadwick

7. Election is discovered by
Ans. JJ Thomson

8. Proton is discovered by
Ans. Rutherford

9. The disease caused by difficiency of iodine is
Ans. Goitre

10. The disease caused by difficiency of protein in children is
Ans . Kwashiorkor

10. The Metal present in haemoglobin is
Ans. Iron

11. The metal present in chlorophyll is
Ans . Magnesium

12. The pH value of human blood is
Ans. 7.4

13. The acid present in vinegar is
Ans. Acetic acid

14 . Which vitamin is responsible for clotting of blood
Ans . Vitamin K

15. Which vitamin is called as beauty vitamin ?
Ans. Vitamin E

16. The harmone secreted by pancreas is
Ans. Insulin

17. Kidney stone is composed of
Ans. Calcium oxalate

18. Lysosomes is known as
Ans. Suicide bag of the cell or Atoms bomb.

19.Who discovered nucleus in the cell.
Ans. Robert Brown

20. The metal present in insulin is
Ans. Zinc

21. The number of muscles present in human body is
Ans. 650

22. Who discovered Antibiotics
Ans. Alexander flaming

23. The disease caused by the difficiency of vitamin D is
Ans. Rickets and Osteomalacia

24. The disease caused by the difficiency of vitamin A is
Ans. Night blindness and Xerophthalmia

25. The chemical name of vitamin A is
Ans. Retinol

♻️ Plasma Membrane Structure and Function ♻️

✅ What is Plasma Membrane?
➖ Plasma membrane is thin, elastic semi permeable living membrane that serves as boundary for the cytoplasm
➖ Plasma membrane was coined by Nageli in 1855
➖ Also known as Cell membrane or plasmalemma
➖ Made up of protein and phospholipids
➖ Selectively permeable in nature
➖ Dynamic membrane

✅ Plasma Membrane Structure
➖ Sandwiched model
➖ Unit membrane model
➖ Fluid mosaic model

1. Sandwiched Model
➖ In 1935, proposed by Davson & Danielli
➖ Oldest model on the structure of plasma membrane
➖ Plasma membrane is made up of three layers
➖ Outer protein layer, middle lipid layer & inner protein layer
➖ Proteins are alpha globular
➖ Lipids are amphipathic
➖ Lipids arranged in bilayer in such a manner that tails face each others
➖ Van der vaal force helping to 2 layers stay together
➖ Proteins on either side of phospholipids bilayers

2. Unit Membrane Model
➖ In 1959, Proposed by Robertson
➖ Plasma membrane is made up of three layers
➖ Outer protein layer, Middle lipid layer & inner protein layer
➖ Proteins are beta fibers
➖ Thickness of plasma membrane is 7.5nm (75Å)
➖ Lipids are amphipathic
➖ Lipids arranged in bilayer in such a manner that tails face each others
➖ Van der vaal force helping to 2 layers stay together
➖ Proteins on either side of phospholipids bilayers

3. Fluid Mosaic Model
➖ In 1972, Proposed by Singer & Nicolson
➖ Made up of protein and phospholipids
➖ Proteins are alpha globular & two types


✅ Function of Plasma Membrane

a) Mechanical Support
➖ It gives shape to the cell
➖ Protects all cell contents

b) Exchange of Materials
➖ Regulate the exchange of materials
➖ It allows need materials to enter the cell
➖ It Send out unwanted materials from the cell

c) Endocytosis
➖ Engulfing of food or foreign particles through the
➖ Plasma membrane
➖ Endocytosis differentiated into two types

d) Exocytosis
➖ Process of exudating secretary products from the cells to outside of the cytoplasm
➖ E.g. Pancreatic cells

Important Facts !

Common types of pollination

chapter 4 notes

✍️Mode of Action of Enzymes

🛑Enzymes

Enzymes (Gk. en = in; zyme = yeast) are proteinaceous substances which are capable of catalysing chemical reactions of biological origins without themselves undergoing any change.
Enzymes are biocatalysts.
An enzyme may be defined as "a protein that enhances the rate of biochemical reactions but does not affect the nature of final product."
Maximum enzymes (70%) in the cell are found in mitochondrion. The study of the composition and function of the enzyme is known as enzymology.


🛑There are two views regarding the mode of enzyme action :

(1) Lock and key hypothesis

(2) Induced fit hypothesis

(1) Lock and key hypothesis : The hypothesis was put forward by Emil Fisher (1894) . According to this hypothesis the enzyme and its substrate have a complementary shape. The specific substrate molecules are bound to a specific site of the enzyme molecule.

(2) Induced fit hypothesis : This hypothesis was proposed by Daniel, E. Koshland (1959).

According to this view, the active sites of an enzyme are not rigid. When the substrate binds to enzyme, it may induce a change in shape of the enzyme molecule in such a way that it is fit for the substrate-enzyme interaction. The change in shape of the enzyme molecules can put strain on the substrate. This stress may help bonds to break, thus promoting the reaction.

⭕️Endoplasmic Reticulum⭕️

(1) Definition: It is well developed electron microscopic network of interconnected cisternae, tubules and vesicles present throughout the cytoplasm, especially in the endoplasm.

(2) Discovery: Garnier (1897) was first to observe the ergastoplasm in a cell. The ER was first noted by Porter, Claude, and Fullman in 1945 as a network. It was named by Porter in 1953.

Golgi Complex
(1) Definition: Golgi complex is made up of various membranous system e.g. cisternae, vesicles and vacuoles.

(2) These are also called golgi bodies, golgisomes, lipochondrion, dictyosomes, Dalton complex, idiosomes or Baker’s body.

(3) These are also called “traffic police” of the cell.

(4) Discovery: First observed by George (1867) but it’s morphological details were given by Camillo Golgi (1898), in nerve cells of barn fowl and cat .

https://youtu.be/A_ApAyARD3I

Video lecture on chapter Life Processes

https://youtu.be/WBLg96l8uW8