Biochemistry and Cell Biology: Key Concepts for Medical and Biological Sciences

biochemistry

The study of chemical processes in living organisms.

importance of biochemistry in medicine

It helps us understand disease, drug action, and body function.

disease

An abnormal condition that disrupts normal body function.

homeostasis

The body's ability to maintain stable internal conditions.

restoration of homeostasis

Through pharmacology/drug design (e.g., insulin for diabetes).

molecular structure

The arrangement of atoms in molecules, which determines their function in cells.

cellular function

The processes that keep cells alive, such as energy production, protein synthesis, and waste removal.

nutrition

Obtaining and using nutrients for growth, repair, and energy.

biological (physiochemical) reactions

Chemical reactions in the body, such as enzyme activity or acid-base balance.

metabolism

All chemical reactions in the body; manages energy flow.

catabolism

The breakdown of molecules to release energy.

anabolism

The building of larger molecules from smaller ones; requires energy.

information transfer

The expression of genetic information (DNA → RNA → protein).

living matter

Animate matter that grows, adapts, reproduces, and maintains organization.

nonliving matter

Inanimate matter that lacks biological processes.

identifying characteristics of living matter

Organization, metabolism, growth, adaptation, response to stimuli, reproduction.

chemical evolution

The idea that life began from simple chemical reactions on early Earth.

Earth's primitive atmosphere

Contained water vapor, methane, ammonia, hydrogen, little oxygen.

primitive molecules formed on early Earth

Simple organics such as amino acids and nucleotides.

A.I. Oparin

Proposed the "primordial soup" theory of life's origin.

Stanley Miller

Ran experiments simulating early Earth; produced amino acids in the lab.

four stages in making the first cell

(1) Small molecules form, (2) macromolecules assemble, (3) membrane-bound structures form, (4) first cells arise.

first type of cell

Anaerobic heterotroph (used organic molecules, no O₂).

smallest component of the body

Atom → molecule → macromolecule → organelle → cell.

breakdown of body systems (levels of organization)

Atom → molecule → organelle → cell → tissue → organ → organ system → organism.

living systems composed of lifeless elements

Nonliving atoms (C, H, O, N) combine to create living structures.

elements abundant in Earth's crust

Oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium.

elements abundant in living organisms

Carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur.

bioelements

C, H, O, N, P, S - the main elements of life.

biopolymers

Biological macromolecules like proteins, nucleic acids, polysaccharides, lipids.

supramolecular systems

Large assemblies of molecules, e.g., cell membranes.

processes of human life

Metabolism, responsiveness, movement, growth, differentiation, reproduction.

six classes of nutrients

Carbohydrates, proteins, fats, vitamins, minerals, water.

evidence for a common ancestor

All organisms share DNA, genetic code, and similar biochemical pathways.

types of chemical bonds

Ionic (transfer of electrons), Covalent (sharing electrons), Hydrogen (weak attraction between H and electronegative atom).

bond polarity

Unequal sharing of electrons; creates partial charges (e.g., water).