Bio SAC Flashcard

Eukaryotes

Organisms whose cells contain a nucleus and other organelles enclosed within membranes.

Prokaryotes

Single-celled organisms that do not have a nucleus or membrane-bound organelles.

Levels of organization in life

The hierarchical structure of biological entities from cells to tissues, organs, systems, and organisms.

Surface Area to Volume Ratio (SA:V)

The ratio that compares the surface area of a cell to its volume; impacts how efficiently a cell can exchange materials.

Adaptation to cell SA:V

Cells develop features such as folding or flattening to increase surface area for better material exchange.

Function of organelles

Organelles carry out specific functions essential for cell survival and operation, such as energy production, protein synthesis, and waste processing.

Difference between animal and plant cells

Plant cells have a cell wall, chloroplasts for photosynthesis, and large central vacuoles; animal cells do not.

Plasma membrane structure

A phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates that regulates entry and exit of substances.

Passive transport

Movement of substances across a cell membrane without the use of energy, including simple diffusion, osmosis, and facilitated diffusion.

Tonicity

The relative concentration of solutes in two fluids, affecting the movement of water across a semipermeable membrane: hypertonic (higher solute outside), isotonic (equal solute), hypotonic (lower solute outside).

Effect of osmosis

In plant cells, osmosis can lead to turgor pressure; in animal cells, it can cause swelling or shrinkage depending on tonicity.

Active transport

Energy-requiring process that moves substances against their concentration gradient; includes endocytosis and exocytosis.

Mitosis

The process of cell division resulting in two daughter cells with identical genetic material.

Cell Cycle

The series of phases (G1, S, G2, M) that a cell goes through as it grows and divides.

Cell Checkpoints

Control mechanisms in the cell cycle (G1, G2, M) that ensure proper division and functioning.

Binary fission

A asexual reproduction method in which an organism divides into two equal parts.

Apoptosis

Programmed cell death that occurs in multicellular organisms to maintain health and development.

Effects of apoptosis failure

If apoptosis does not occur correctly, it can lead to cancer or other diseases due to uncontrolled cell growth.

Mutagens

Agents that can cause changes in the DNA sequence, potentially leading to mutations and cancer.

Stem cells

Cells with the ability to differentiate into various types of cells; categorized as totipotent, pluripotent, and multipotent based on their potential.

Specialization/Differentiation

The process by which stem cells develop into specialized cells with specific functions in the body.