Human and Plant Nutrition

Flashcards covering the human digestive system, nutrition, and photosynthesis, based on lecture notes.

Nutrition

The process by which organisms obtain food and energy for growth, repair, and maintenance.

Ingestion

Feeding or taking food into the body.

Digestion

Breaking down large food molecules into smaller, soluble ones.

Absorption

Absorbing digested food substances into body cells.

Assimilation

Converting absorbed food into new protoplasm or using it for energy.

Alimentary canal.

A nine-meter-long tube from the mouth to the anus.

Salivary glands

Secretes saliva into the buccal cavity.

Pharynx

Connects the buccal cavity to the oesophagus and larynx.

Epiglottis

A flap-like tissue that prevents food from entering the trachea.

Oesophagus

A narrow, muscular tube that passes food to the stomach.

Peristalsis

The rhythmic, wave-like muscular contractions that propel food along the alimentary canal.

Stomach

A distensible muscular bag that stores food and secretes gastric juice.

Gastric glands

Secretes gastric juice into the stomach cavity.

Pyloric sphincter

A ring of muscle that controls the passage of food from the stomach to the small intestine.

Duodenum

U-shaped, where the bile duct and pancreatic duct connects to.

Colon

The main function is to absorb water and mineral salts.

Rectum

Stores feaces temporarily.

Pancreas

Produces pancreatic juice, which contains digestive enzymes, and hormones.

Gall bladder

Stores bile temporarily.

Digestion

Breaking down large food molecules into smaller, soluble molecules via physical and chemical processes.

Physical digestion

The mechanical break-up of food into small particles.

Chemical digestion

The breaking down of large molecules in food into small, soluble molecules via hydrolytic reactions catalysed by digestive enzymes.

Pepsin

Digests proteins to polypeptides in the stomach.

Pancreatic Juice

Produced by the pancreas and contains enzymes to break down carbohydrates, proteins and fats.

Bile salts

Speeds up the digestion of fats.

Simple sugars

End-products of carbohydrate digestion.

Amino acids

End-products of protein digestion.

Fatty acids and glycerol

End-products of fat digestion.

Emulsify

Breaks fats into tiny droplets.

Absorption

The process whereby digested food substances are absorbed into the body cells.

Villi

Finger-like projections on the inner surface of the small intestine that increase the surface area for absorption.

Lacteals

Lymphatic capillaries in the villi that transport fats.

Egestion

Removal of undigested matter from the body.

Assimilation

The process whereby some of the absorbed food substances are converted into new protoplasm or used to provide energy.

Hepatic portal vein

Transports nutrients to the liver.

Urea

Excess amino acids are deaminated in the liver, producing.

Adipose tissues

Tissues that store excess fats.

Alcohol dehydrogenase

Breaks down alcohol to acetaldehyde.

Detoxification

Conversion of harmful substances into harmless ones.

Deamination

Conversion of amino groups from amino acids into urea.

Chlorophyll

Traps light energy and converts it into chemical energy.

Photosynthesis

Process where light energy absorbed by chlorophyll turns into chemical energy.

Autotroph

An organism that builds up complex organic molecules from simple inorganic molecules.

Heterotrophs

Organisms that are unable to manufacture their own food.

Destarching

Removal of starch.

Photolysis

Split water to oxygen and hydrogen atoms.

Pigment

Absorbs sunlight.