Metabolism, Enzymes, and the Endocrine System Overview

Metabolism

All chemical reactions involved in maintaining the living state of the cells and the organism.

Anabolic reactions

Reactions where energy is stored.

Catabolic reactions

Reactions where energy is released.

Enzymes

Proteins that speed up reactions that occur in living systems.

Lock and key model

Enzymes have an active site that is complementary to only one substrate.

Factors affecting enzyme activity

Enzymes have a specific set of conditions that will favour their action on the substrate and where they function optimally.

Denaturing

The process where the enzyme shape changes, preventing it from functioning.

Temperature effects on enzymes

If temperatures are too high, the enzyme shape changes, preventing it from functioning. If temperatures are too low, the enzyme has not got enough kinetic (movement) energy to collide with the substrates as often and therefore action is reduced.

pH effects on enzymes

The rate of reaction increases to the optimum (maximum) point and then decreases either side of this.

Digestion

Enzymes are involved in the process of digestion, breaking down food into simple chemical substances.

Carbohydrates breakdown

Carbohydrates are broken down into glucose.

Proteins breakdown

Proteins are broken down into amino acids.

Lipids breakdown

Lipids are broken down into fatty acids and glycerol.

Rate of reaction with increased enzymes

The rate of reaction increases. The reaction will stop when all of the substrates have been turned into products.

Rate of reaction with increased substrates

The rate of reaction increases until all of the available active sites are filled (substrates have to wait until an active site becomes available).

Endocrine System

Controls specific functions of the human body by the use of chemical substances called Hormones produced in various endocrine glands.

Pituitary Gland

The entire Endocrine System is coordinated by the pituitary gland, which is linked with the CNS by the hypothalamus.

Role of the Hypothalamus

Checks internal environment, responds to changes, links nervous system to endocrine system by secreting hormones which act on the pituitary gland.

Processes Controlled by Hypothalamus

Controls body temperature, metabolism, water levels.

Role of the Pituitary Gland

Secretes a variety of hormones and controls other glands.

Endocrine Glands

Testis, Pancreas, Thymus, Adrenal, Hypothalamus, Thyroid & parathyroid, Pituitary, Ovary.

Hormones

Hormones instruct cells to make changes that restore the body-balance.