Cell Theory and Microscopy Quiz

Introduction to Biochemistry

• Biochemistry studies chemical substances and interactions in living organisms, focusing on the components of life (bio) and chemical interactions (chemistry).
• The term "Biochemistry" was first coined by Carl Neuberg, who is recognized as the Father of Modern Biochemistry.

Historical Development

• Emergence dates to the late 18th and early 19th centuries, with clinical biochemistry developing as an independent field in the 1940s.
• Key pioneers and discoveries from various years include:
  • 1835: Berzilus on enzymes catalysis
  • 1897: Edward Buchner on enzyme extraction
  • 1921: Banting and Macleod discovered insulin
  • 1953: Watson and Crick described the structure of double-stranded DNA
  • 1985: Kary Mullis developed the Polymerase Chain Reaction (PCR)

Chemical Elements of Life

• Approximately 25 elements are deemed essential for life, with four main elements (C, O, H, N) constituting about 96% of the human body.
• Living matter is composed of biogenic elements, which include:
  • Macrobiogenic elements: (>0.1% in organisms) provide structure (e.g., C, O, H, N, S, P, Na, K, Ca, Mg, Cl, Fe).
  • Microbiogenic elements: (<0.1% in organisms) handle catalytic functions (e.g., Cu, I, Mo, Mn, Zn, Co).
  • Trace elements: (<0.001% in organisms) also serve catalytic roles and are parts of enzymes (e.g., Al, As, B, Br, F, Li, Ni, Se, Si, Ti, V).

Cell Theory

• The foundational Cell Theory began with observations by key scientists:
  • Matthias Schleiden: all plants are made of cells (1838).
  • Theodore Schwann: all animals are composed of cells (1839).
  • Rudolph Virchow: all cells arise from pre-existing cells (1855).
• Modern Cell Theory highlights:
  • All living organisms consist of one or more cells.
  • All metabolic processes occur within cells.
  • Cells only originate from division of existing cells.

Cell Basics

• The smallest unit of life capable of performing biological functions, with sizes typically ranging from 5 to 50 micrometers.
• Organisms can be unicellular (single-celled) or multicellular (many cells organized into tissues).

Types of Cells

• Prokaryotic cells: Simple, lack membrane-bound structures, examples include bacteria.
• Eukaryotic cells: More complex, have a nucleus and membrane-bound organelles, include animals, plants, fungi, and protists.

Key Cell Components

• The cell membrane is a phospholipid bilayer controlling entry/exit of substances and facilitating communication.
• Organelles perform specific cellular functions like energy production (mitochondria), and photosynthesis (chloroplasts).
• The nucleus regulates activities, contains DNA, and is surrounded by a nuclear envelope.

Membrane and Organelles

• Cell walls provide structure in plants, fungi (made of chitin), and bacteria (made of peptidoglycan).
• Glycoproteins help in cell recognition and communication.
• Centrioles assist with cell division and formation of cilia/flagella.

Reactions in Biochemistry

• Hydrolysis and condensation reactions involve breaking down larger molecules (hydrolysis uses water) and combining smaller ones (condensation releases water).
• Esterification combines organic acids and alcohols to form esters.
• Decarboxylation removes a carboxyl group and releases CO2.

Summary

• Biochemistry integrates chemistry and life sciences, examining the molecular foundations of biological processes, emphasizing the importance of cellular structures and functions.