Common Requirements of living things - ANIMALS – Chapter 5

Common Requirements of living things - ANIMALS – Chapter 5

Movement of substances into & out of unicellular organisms

Passive diffusion in and out

Bulk Transport requiring energy

Cell Specialisation in Simple Multicellular Organisms

Sponge feeding

Cell Specialisation in Simple Multicellular Organisms

Cnidarians feeding

Cell Specialisation in Simple Multicellular Organisms

Cell Specialisation in Vertebrate Multicellular Organisms

Cell Specialisation in Vertebrate Multicellular Organisms

The different systems!Animal’s bodies are

composed of different systems, each system has

it’s own functions. All together these systems

work together to enable the animal to survive.

http://video.nationalgeographic.com/video/player/science/health-human-body-sci/human-body/human-body-sci.html

Obtaining nutrients and energy• Animals are heterotrophs must consume food in order to

obtain nutrients and energy.• Animals are adapted to obtain food in a variety of ways

python vs croc

Required Nutrients

• Carbohydrates - source of immediate energy for all living organisms. The monosaccharide glucose is broken down to make ATP in cellular respiration.

• Lipids- Fats and oils required for cell membranes, hormones and vitamins.• Amino Acids - The building blocks of proteins. The body can make some

amino acids but others it can’t make these are the 9 essential amino acids. Need to be regularly eaten.

• Vitamins - Organic compounds needed for cellular processes, e.g. making enzymes.

• Minerals - needed for structural components and for enzyme molecules.

The Digestive System• Ingestion- intake of food into the body• Digestion- physical and chemical breaking down of food• Absorption- nutrient molecules move into the circulatory

system and ultimately into the cells.• Egestion/ Elimination- removal of waste from the body

Two Types of Digestion.Physical digestion.

– Food physically broken it down into smaller pieces in order to increase surface area and enable maximum efficiency of chemical digestion.

Teeth

Chemical DigestionBreakdown of macromolecules by enzymes- made in the gut, salivary glands and pancreas into molecules small enough to be absorbed through the alimentary lining.

Amylases- Break down carbs- maltose

Proteases- Break down protein-

Lipases- Break down lipids

http://health.howstuffworks.com/human-body/systems/digestive/adam-200086.htm

Introduction to the Human Alimentary System animation

Digestion• Stomach - majority of digestion occurs

– Mechanical digestion occurs as the muscles crush and move the food.– Chemical digestion also occurs in the stomach, with the secretion of

gastric juices with have enzymes that break down the food.• Small intestine -further digestion occurs but only on proteins and

carbohydrates to break them down into their amino acid building blocks.

Digestion-video.htm

AbsorptionMost occurs in the small intestine. Food at it’s smallest is then absorbed by the cells of the intestine and passed along to the blood stream.

Other mammals• Different diets require different digestive systems. • Breaking down cellulose requires the enzyme cellulase. • Mammals can’t make this enzyme.• Cows have a 4 chambered stomach. • They chew and then regurgitate their food and chew it again before sending it

to the rumen where heaps of cellulose digesting bacteria live and allow the breakdown of the cellulose to occurs.

Carnivore v Herbivore

Caecum: a pouch extension at the junction of the small & large colon which in herbivores contains cellulose digesting bacteria.

Herbivorus mammals with higher fibre diets may have larger caecums to maximise the opportunity for cellulose digestion by bacteria.

Digestion in birdsMost (not all) birds have :• a crop for temporary storage • a glandular part the proventriculus which

secretes mucus , HCl & enzymes• a muscular gizzard which may contain grit or

small stones which grinds and mixes the food and enzymes etc.