LIFE PROCESSES

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What are the characteristics of life?

The seven life processes1 Move1 Move

2 Reproduce2 Reproduce

3 Sensitive3 Sensitive

4 Nutrition4 Nutrition

5 Excrete5 Excrete

6 Respire6 Respire

7 Grow7 Grow

Difference between living and non-living thing

LIVING THINGS NON-LIVING THINGS

Movement- body, molecules

Even though there is movement they are not alive.

Nutrition It is not taking place.

Excretion There is no excretion.

Growth Growth is not taking place.

Respiration – breathing There is no respiration.

Reproduction It is not taking place.

Sensitivity There is no sensory organs.

What is a living thing?Imagine that you are space traveler who

lands on an unknown planet. How could you determine if what you are looking at is alive. Ex. A rock and a blade of grass.

What are the life processes?NUTRITIONTRANSPORTRESPIRATIONEXCRETIONSYNTHESISGROWTHREGULATIONREPRODUCTION

Nutrition

Includes the activities involved in ingestion (obtaining food from the environment) and digestion (processing food for use by the organism). It also includes egestion (removal of solid wastes)

How organisms grow? Living organisms need to grow, they need

energy for living and growth.

This is accomplished by breaking down

food to produce energy.

Life on earth depends on obtaining energy

by breaking down carbon-based compounds

(carbohydrates, fats and proteins).

FATS

CARBOHYDRATES

PROTEINS

ENERGY

OXIDATION- REDUCTION REACTIONS

Energy

Molecular movements inside cells

Maintaining living structures

Growth of body

To run series of biochemical reactions inside cells

Chemical reactions inside cells Oxidation-reduction reactions are most

common inside cells to breakdown molecules of

glucose or fatty acid or amino acid (molecules

used by cells).

These reactions use oxygen.

Living organisms use oxygen to carryout

oxidation-reduction reactions, so they are

called as cellular respiration.

How do organisms obtain their nutritionSingle cellular organismsThese organism live with one cell.They carry out all life processes with

its single cell.They are not having any specific organ system for taking in food, exchange of gases or removal of wastes.

The entire surface of the organism is in contact with the environment.

Single cellular organisms carryout Simple Diffusion process to meet some of the life processes.

Nutrition in amoeba

Multicellular organismsMulticellular organisms are

organisms that consist of more than one

cell, in contrast to single-cell organisms.

To form a multicellular organism, these

cells need to identify and attach to the

other cells.

Multicellular continues….All cells are not in direct contact with

environment.Simple diffusion is insufficient and will

not meet the requirements of all the cells.

FOOD OXYGEN

Body cells need both to perform biochemical reactions to produce energy

Digestive system digests complex food and absorbs simpler form of nutrients and then transported to cells.

Respiratory system is responsible for inhaling O2. Then O2 is transported to all cells.

Transport system

Excretion

Nutrition

How do living things get their food?Green plants and some bacteria make

their own food. They use raw materials like water and

carbon dioxide(inorganic raw materials).Green plants and some bacteria are

autotrophs.

What is an autotroph?An organism capable of making its own food from inorganic substances, using light or chemical energy. Plants are autotrophs. They take in light (the sun) and convert this into food or energy. E.g. plants , bacteria and algae.

What is a heterotroph?An organism that must ingest complex organic substances in order to create energy. These organisms use biocatalysts called enzymes. Examples of heterotrophs are humans. Humans must ingest food in order to create energy. They do this through digestion. Other e.g. animals, fungi.

Photosynthesis in equation

Events occur during photosynthesis

Absorption of light energy by chlorophyll.

Conversion of light energy into chemical energy.

Splitting of water molecules into Hydrogen and oxygen and 1pair of electrons.

Desert plants takes up carbon dioxide

and prepare starch at night.

Light energy is absorbed by the

chlorophyll during day time.

Nutrition in green plants Green plants are also called autotrophic

organisms, as they can produce their own food.

Autotrophic = auto+ trophic, means- making food by self without depending other living beings.

Green plants produce food by photosynthesis process, so they are known as producers in the environment.

Starch test

Leaves tested for starch-IODINETEST

Variegated leaf

Opening and closing of stomataStomata: They are tiny openings or

pores, found mostly on the underside of

a plant leaf and used for gas exchange.

The pore is formed by a pair of

specialized cells known as guard cells

which are responsible for regulating

the size of the opening.

glucose NITROGEN

Amino acids

Roots of leguminous plants can absorb

nitrate / nitrite compounds (nitrogen

source) from the soil.

Rhizobium bacteria helps in converting

atmospheric nitrogen into organic

nitrates/nitrites.

Heterotrophic nutritionHeterotrophic nutrition is classified into three

types : (i) Saprophytic nutrition (ii) Parasitic

nutrition (iii) Holozoic nutrition.

SAPROPHYTIC NUTRITION : Organisms

obtaining nutrients from dead and decaying

organic matter are called saprophytes and their

mode of nutrition is called saprophytic

nutrition. Many species of bacteria and

different types of fungi are saprophytes.

Heterotrophic nutrition in non green plantsTypes: Saprophytes: These organisms get

their food from dead and decaying plants and animals.

They release digestive enzymes to break down complex organic matter into simpler ones.

E.g. Fungi, Bacteria.

PARASITIC NUTRITION : If an organism depends on another living organism for nutrition, its mode of nutrition is called parasitic nutrition. Such organisms are called parasites and the organism from which they obtain nutrition is called host. The host organism is harmed by the parasite. Parasitic nutrition is observed in some bacteria, fungi, flowering plants like cuscuta and animal like ascaris.

Cuscata (amber -bel)

leeches

HOLOZOIC NUTRITION : Holozoic

nutrition involves intake of parts of

plants or animals or an organism

as a whole by the process of

ingestion which is then digested

and absorbed. Some examples are

amoeba, frog, insects, human

being, etc.

Nutrition in humansDigestion: The conversion of complex food into simple soluble forms.

Parts of digestive system:

Teeth – biting, chewing food.

Alimentary canal - it consists of

several organs oesophagus, stomach, the

small and large intestines, rectum and

anus.

Digestive glands - secrete digestive

juices.

Human Nutrition

INGESTION taking of food into to the mouth

DIGESTION break down of food into small soluble

pieces

ABSORPTION taking in of useful food into the bloodstream

ASSIMILATION use of food for growth, repair and energy

EGESTION removal of unused food from the body.

NUTITION IN HUMAN BEINGSHuman alimentary canal

Identify the labellings

Location of the salivary glands in mouth

Digestion in mouthWhat happens in mouth?

Grinding of bolus by teeth

S alivary glands produce salivaSaliva

contains salivary amylaseStarch maltose

Digestion of starch in mouth

Peristalsis

Peristaltic waves of contraction push food through the lower esophageal sphincter into the stomach.

Peristaltic waves of contraction push food through the lower esophageal sphincter into the stomach.

Parts of stomach

Gastric glands and mucous membranes

Digestion in stomach

CHYME: when stomach churns food, it is converted into semi solid state.

Digestion in stomachPepsin action is favored by HCl, mucus protects inner lining of stomach

main digestive enzymes found in our bodyS.NO Digestive

organEnzyme/juice Food

acted upon

Substances produced.

1. Mouth (salivary glands)

Salivary amylase Starch Maltose (sugar)

2. Stomach Gastric juice -Pepsin

Proteins Peptides (fragments of protein)

3. Pancreas Pancreatic juice:•Amylase•Trypsin •Lipase

•Starch •Proteins •Fats (lipids)

•Maltose (sugar)•Peptides (very small fragments)•Fatty acids+ glycerol

4. Small intestine

•Lipase •Maltase •Sucrase •Peptidase

•Fats •Maltose •Sucrose•Peptides

•Fatty acids+ glycerol•Glucose •Glucose and fructose•aminoacids

Small intestine structure

Absorption in the small intestines

Assimilation

It is the final stage of digestion.

When the soluble food absorbed into the

blood stream is used to provide energy

and materials for growth and repair of

body tissues.

assimilationFood material Assimilation

Glucose •Provides energy. •Stored in liver and muscles.

Fatty acids+ glycerol

•Energy reserves.•It is stored in liver and in under skin.

Amino acids •Repairs damages in body parts.• Forms enzymes, hormones.•Responsible for growth

Egestion The removal of undigested food or

waste moves to large intestines

where water is absorbed from them,

making a semi solid. This is Faeces.

It is stored in the large intestine called

rectum.

It is sent out of the body through anus.

RESPIRATIONThe process of releasing energy from

organic molecules for use by cells.

During respiration glucose is broken down, and the energy released is stored in the compound ATP.

Energy released by the compound ATP is used by organisms to perform life functions.

Respiration is the release of energy from

glucose or another organic chemical.

Aerobic Respiration requires oxygen.

Anaerobic Respiration does not require

oxygen and releases less energy.

Respiration Respiration: is the release of energy from food,takes place in animal and plant cells.Aerobic Respiration requires: Glucose,

Oxygen.Aerobic Respiration produces: Energy,Carbon Dioxide, Water.Anaerobic Respiration requires: Glucose.Anaerobic Respiration produces: Energy (not as much),Carbon Dioxide,Lactic Acid or Alcohol.

Anaerobic respiration

C6H12O6 2C2 H5OH +

ethanol 2CO 2 +

Energy Yeast can carry out respiration in the absence of

oxygen.

Anaerobic respiration in humansDuring vigorous physical exercise.

Glucose Lactic acid + Energy

In cytoplasmGlucose

(6C)Pyruvate (3C) + Energy

Lactic acid (3C) + Energy

BREAK DOWN OF GLUCOSE BY ANAEROBIC PATHWAYS IN MUSCLE CELLS

Lack of oxygen in muscle cells

In cytoplasmGlucose

(6C)Pyruvate (3C) + Energy

Ethanol (2C) + CO2 + Energy

Absence of oxygen in yeast

ANAEROBIC PATHWAY FOR GLUCOSE BREAK DOWN IN YEAST

In cytoplasmGlucose

(6C)Pyruvate (3C) + Energy

Water + CO2 + Energy

Presence of oxygen in mitochondria

Aerobic pathway for glucose break down in mitochondria

Aerobic respiration Anaerobic respiration

Presence of oxygen. Absence of oxygen.

6 Carbon glucose 3Carbon pyruvate CO2, water inside mitochondria.

6 Carbon glucose 3Carbon pyruvate ethanol or lactic acid in cytoplasm.

More energy is released. Very less energy is released.

It takes place in most of cells like RBC, Brain cells, heart muscle cells.

It takes place in yeast (ethanol fermentation), muscle cells (lactic acid) muscle cramps during muscle exercise.

Types of respiration

What form of energy used by cells?The energy used during cellular

respiration is used to synthesis ATP.

ATP – Adenosine Tri Phosphate

(currency of cells)

ATP is the fuel to all cell activities.

ATP s are broken down to release energy

which can be used by cells to carry out

movement in molecules, biochemical

reactions.

Endothermic reactions (reactions that absorbs heat from outside source) use ATP to drive their reactions.

The terminal phosphate linkages are broken down using water (hydrolytic reactions).

1 ATP = 30.5 KJ/mol is released.ATP can be used for: Muscle contractionProtein making and cell repairsConduction of nerve impulse messagesMolecules to enter and exit plasma membrane.

ADP + PHOSPHATE

ADP~PHOSPHATE

ATP

Energy

Diffusion The process by which molecules spread

from areas of high concentration, to areas

of low concentration. When the molecules

are even throughout a space - it is called

EQUILIBRIUM.

Diffusion contd…..Molecules will always move down the

concentration difference, toward areas of

lesser concentration. Think of food coloring

that spreads out in a glass of water, or air

freshener sprayed in a room.

Water movement in plants

Diffusion in plantsPlants exchange gases through stomata.The large intracellular space ensures cells

are in contact with environment air. CO2 and O2 are exchanged by diffusion

here.Direction of diffusion depends on

environmental conditions and requirements of plants.

Night no photosynthesis occurs CO2 exchange.

Day CO2 used by plants Photosynthesis no CO2 released to air. O2 is released.

Diffusion in terrestrial animalsAnimals respire using different organs.Terrestrial animals use lungs for breathing.These animals have respiratory system.That has large surface area that is in close

contact with air as well as they are protected

inside our body, because they are so delicate

to carry out diffusion of gases.These organs have special mechanism to

carry out breathing and diffusion of gases

Diffusion in aquatic animalsBreathing rate is comparatively faster in aquatic animals.Takes in water by mouth

Respiration in humans

Gas exchange in alveoli

The circulatory system in humans3 distinct components

Blood - fluid circulates in our body.

Blood vessels- tubes that help the blood to

circulate.

Heart - pumping organ that

circulates the blood around

the body.

Composition of blood

PLASMA (55%)

BLOOD CELLS(45%)

Red blood cells (Erythrocytes)

White blood cells (Leucocytes)

Platelets (thrombocytes)

Red blood cellsDisc shaped.O2 and CO2 transport.1 cubic millimetre of blood has5 million RBC.Haemoglobin

White blood cellsColourless and larger than RBC.Protects your body against infection by killing bacteria.

HUMAN HEART

Pulmonary artery

Pulmonary vein

septum

Single circulation in fishes, amphibians and reptiles

Blood pressure

Blood pressure

Force exerted by blood on the walls of artery.

It is greater in arteries than in veins.

The Pressure of blood inside the artery

during ventricular systole (contraction) is

called systolic pressure.

Pressure in artery during ventricular

diastole (relaxation) is called diastolic

pressure.

The normal systolic pressure -120mm Hg.

The normal diastolic pressure-80 mmHg.

Maintenance by platelets

Lymph Lymph or tissue fluid is involved

in transportation.

The almost colourless fluid that bathes

body tissues and is found in the lymphatic

vessels that drain the tissues of the fluid

that filters across the blood vessel walls

from blood. Lymph carries lymphocytes

that have entered the lymph nodes from

the blood.

Transport in plants

Water absorbed into roots through root hair

cells

Water carried to leaves through xylem vessels

Water evaporates from underside of leaves

Water escapes through holes called stomata

As water evaporates, more is sucked up xylem

Stomata open and close to control water loss

Open – O2 and CO2 enter and exit

Closed – Reduce water loss

 

Water is absorbed in plants by young roots and

in the dermal cells by osmosis

Cell sap of the epidermal cells has higher

concentration than water in the soil

Root hairs significantly increase water

absorption

Root hairs increase the root surface area and

catchment space for water uptake

Epidermal cells do not have a cuticle > water

uptake is fast

Diffusion and osmosis

osmosisVisit the site: http://www.youtube.com/watch?v=yYx_9y0I1Hg&feature=related

Osmosis in plants

transpiration

Transport of food and other substances

Excretion in humans

i) Kidneys Place of filtration and reabsorption

ii) Ureter

Urine flows from the collecting tubes in the kidneys

to the ureter (a pipe)

iii) Urinary Bladder

Urine flows from ureter to this place where it is

temporarily stored

iv) Urethra

Periodically, urine is EXCRETED from the bladder

through the urethra

Urine formation

EXCRETION

Oxygen- waste product. Photosynthesis

Excretion in plants

Water – transpiration

Dead cells/waste stored in leaves - removed by falling leaves

Waste products are stored in cellular vacuoles

Plants excretes waste into soil