Cell Theory and Organization

Flashcards about cell theory, functions of life, cell size, magnification, microscopes, emergent properties, and cellular organization.

Cell Theory

Living organisms are composed of cells (or cell products); The cell is the smallest unit of independent life; Cells can only arise from pre-existing cells.

Striated Muscle (as a caveat to Cell Theory)

Composed of fused cells that are multinucleated.

Giant Algae (as a caveat to Cell Theory)

Unicellular organisms that are very large in size (~7 cm).

Aseptate Hyphae (as a caveat to Cell Theory)

Lack partitioning and have a continuous cytoplasm.

Functions of Life (carried out by single-celled organisms) MRSHENG

Metabolism, Reproduction, Sensitivity, Homeostasis, Excretion, Nutrition, Growth

Cell Size Limitation

Surface area to volume ratio is important in the limitation of cell size. Cells need to exchange materials with the environment to produce chemical energy.

Metabolic Rate & Cell Size

The rate of metabolism is a function of a cell’s mass / volume.

Material Exchange & Cell Size

The rate of material exchange is a function of a cell’s surface area.

Small SA:Vol Ratio

Implies a high metabolic rate and low material exchange, leading to low survival chances

Large SA:Vol Ratio

Implies a low metabolic rate and high material exchange, leading to high survival chances

Magnification (MIA Formula)

Magnification = Image Size ÷ Actual Size

Actual Size (AIM Formula)

Actual Size = Image Size ÷ Magnification

Light Microscope

Uses lenses to bend light; can view living specimens in natural colour; has lower magnification and resolution.

Electron Microscope

Uses electromagnets to focus electrons; can only view dead specimens in monochrome; has higher magnification and resolution; can show cross-sections (TEM) or surface renderings (SEM).

Emergent Property

A function that is present in multicellular organisms, but is not present in its individual component cells; arises from synergistic interactions between individual cells.

Bacterial Biofilms Antibiotic Resistance

Increased levels of antibiotic resistance is an example of Emergent Property

Cellular Organization

In multicellular organisms, cells may be grouped together to form tissues; tissues may interact to form functional organs; organs may combine to form body systems.

Muscle, Cardiac, Heart, Vascular

Cell, Tissue, Organ, System respectively