Lomio&Namas

HOW CAN WE KNOW THAT SOMETHING IS ALIVE? If it performs the vital functions: nutrition, interaction, reproduction

Nutrition
-the intake of SUBSTANCES from outsideoutside
substances we don't burn but store

To grow To renew our body

substances we burn

To get energy For other muscles to contract -heart
pumping, respiratory mucles, digestive muscles...

To move our skeletal musclesFor brain activity

To keep the body temperature

And how can we obtain energy from some susbstances we take in ?
A chemical reaction similar to combustion happens in cells
Fuels -combustibleswood, paper, petrol
-all containing C in their composition-

+

oxygen
O2

combustion

carbon dioxide +

ENERGY

“ matter neither appears from nowhere nor disappears to nothing ”-matter conservation law(la materia ni se crea ni se destruye: si había carbono en la composition del combustible, habrá carbono en alguna de las sustancias resultantes de la reacción

And how can we obtain energy from some susbstances we take in ?
Cellular respiration is a process similar to combustion. Cellular respiration takes places in..
Cell fuel -glucose, fats...-all containing C in theircomposition-

+

oxygen
O2

Cellular respiration

carbon dioxide +

ENERGY

Why do cells need oxygen? Why do living beings produce CO2?

C6H12O6
glucose

O2

CO2
+

H20
+

C6H12O6
glucose

O2

CO2
+

H20
+

Cell fuel -glucose, fats...containing

C
+ 6 O2
Cellular respiration

for example

C6H12O6

6 CO2 + 6 H2O +
ENERGY

And HOW DO CELLS GETTHEIR FUELS?

?

In a different way if they are autotrophic or they are heterotrophic

HOW do animals, fungi, protozoa and some bacteria GET THEIR FUELS? Cell fuel -glucose, fats...containing

C
+ 6 O2
Cellular respiration

for example

C6H12O6

6 CO2 + 6 H2O +
ENERGY

?In HETEROTROPHIC NUTRITION, by eating
organic matter from other organisms -look at the 3 following slides-.For example, to get glucose a HETEROTROPHIC organism can take in carbohydrates in its food.

Intake of complex organic matter

Simple organic matter Fuel TO BURN or substance TO STORE -growth and renewalheterotrophic Monosaccharide Polysaccharide* STARCH organisms GLUCOSE IN SEEDS -beans, peas, C6H12O6 after digestion wheat, rice...-

Disaccharide SUCROSE -sugar is pure sucroseor LACTOSE-in milk-

No need for digestion

*watch next slide!

Monosaccharide FRUCTOSE C6H12O6 in fruits Intake of simple organic matter

Intake of complex organic matter

Simple organic matter Fuel TO BURN or substance TO STORE -growth and renewalheterotrophic Monosaccharide Polysaccharide* STARCH organisms GLUCOSE IN SEEDS -beans, peas, C6H12O6 after digestion wheat, rice...-

DisaccharideSUCROSE -sugar is pure sucroseor LACTOSE -in milk-

No need for digestion

*watch next slide!

Monosaccharide FRUCTOSE C6H12O6 in fruits Intake of simple organic matter

Polysaccharide CELLULOSE in ALL PLANTS as part of the cell walls

Fuel TO BURN or heterotrophic substance TO STORE organisms -growth and renewalMonosaccharide Herbivores and FUNGI can digest GLUCOSE cellulose so theyC6H12O6 can get glucose
from cellulose Other animals* CANNOT digest cellulose so they CANNOT get glucose from cellulose*

* in non-herbivore animals, cellulose is called FIBER = FIBRE /faibe/. It is not a nutrient because non-herbivores can not digest it, cellulose remains (permanece) as a big molecule and it can not be absorbed to blood. Although cellulose can not be digested by non-herbivores,it's important in diet because fiber prevents from constipation (estreñimiento) The reason for this is that cellulose retains (retiene) water -as paper doesand feces contain a higher amount of water and are easier to expel.

Complex organic matter

Simple organic matter
HETEROTROPHIC organisms after DIGESTION

Starch in...

Fuel TO BURN or substance TO STORE -grow and renewal-

HOW do...