Post on 13-Jul-2020
All animals eat. What happens to the food that they
eat?
1
Animals use food in two ways
2
Food Digestion
Materials for growth:
Biosynthesis
Energy: Cellular
respiration
How do animals use food as materials for growth?
3
1. What is food made of?
2. What are animals made of?
3. How can animals make themselves from the food they eat?
Food is mostly water and large organic molecules
FATS
STARCH
PROTEINS
CARBOHYDRATES:
FIBER
Animals are mostly water and different large organic molecules
FATS
PROTEINS
How can animals make their molecules from food molecules?
Materials for growth:
Biosynthesis
Energy: Cellular
respiration
Step 1: Digestion
6
Food Digestion
Answering the Three Questions for Digestion
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Where are atoms moving from?
Where are atoms
moving to?
Digestion: The Movement Question
Which atoms and molecules move when an animal digests food?
Small organic molecules
Large organic molecules
Small organic molecules
Large organic molecules
How do large and small organic molecules move when an animal digests food?
What happens to food that animals can’t digest?
11
Our digestive systems cannot break down some large organic molecules (such as fiber). These molecules leave our bodies as feces.
What is happening to carbon atoms? What is happening to
chemical energy?
Digestion: The Carbon and Energy Questions
Chemical change
Products Reactants
Large organic molecules (+ water)
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What happens to carbon atoms and chemical energy in digestion?
Small organic molecules
Chemical change
Products Reactants
Large molecules (+ water)
14
What happens to carbon atoms and chemical energy in digestion?
Small organic molecules
Carbon atoms stay in organic molecules with
high-energy bonds
Materials for growth:
Biosynthesis
Energy: Cellular
respiration
Step 2: Biosynthesis
15
Food Digestion
Answering the Three Questions for Biosynthesis
16
Small organic molecules
Large organic molecules
The Movement Question: How do animal cells use small organic molecules to grow and divide?
The Carbon and Energy Questions: What happens to carbon atoms and chemical
energy during biosynthesis?
The Carbon and Energy Questions:
Chemical change
Small organic molecules go into cells, but don’t come out. What happens inside the cells?
Chemical change
Products
Large organic molecules (+ water)
Reactants
19
What happens to carbon atoms and chemical
energy in biosynthesis?
Small organic molecules
Chemical change
Products
Large molecules (+ water)
Reactants
20
What happens to carbon atoms and chemical
energy in biosynthesis?
Small organic molecules
Carbon atoms stay in organic molecules with
high-energy bonds