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

Most reef-building corals have a symbiotic relationship with photosynthetic algae, called zooxanthellae. which live in their gastrodermis tissue. The zooxanthellae convert sunlight, carbon dioxide, and water into oxygen and carbohydrates that feed the coral polyps and help them produce reef-building calcium carbonate. In return, the corals provide the zooxanthellae with protection and the compounds they need for photosynthesis. Pigments in zooxanthellae also give corals their beautiful orange, red, purple, and yellow colors. Corals

Cell Specialisation in Simple Multicellular Organisms Cnidarians feeding

Cell Specialisation in Simple 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. eo/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 Digestion Breakdown 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 starches into simple sugars Proteases- Break down protein-into amino acids Lipases- Break down lipids into glycerol & Fatty acids

Introduction to the Human Alimentary System animation Human digestion overview

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

Absorption Most 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 birds Most (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.