Cell Structure and Functions

Practice flashcards covering cell definitions, broad divisions, nuclear structures, and the functions of various organelles mentioned in the lecture.

Cell

The basic structural and functional unit of life, often described as the building block of life.

Cell membrane

The outer boundary of a cell that acts as a gate to control the substances that enter and leave.

Nucleus

The control center or chief center of the cell where genetic materials are stored.

Cytoplasm

A jelly-like substance inside the cell where various organelles are found.

Organelles

Meaning small organs, these are specialized structures located within the cytoplasm of a cell.

Nuclear envelope

The structure formed by the combination of the outer layer and the inner layer of the nucleus.

Nuclear pores

Holes or passage-ways in the nucleus through which substances enter and leave.

Nucleolus

A dense structure found inside the nucleus that helps in the production of ribosomes.

Chromatin

A structure inside the nucleus composed of $DNA$ and proteins, specifically histone proteins.

Histone proteins

The specific type of proteins that are found inside the chromatin of the nucleus.

$$DNA$$

Standing for deoxyribonucleic acid, it is the genetic material found within the nucleus.

$DNA$ replication

The process by which a $DNA$ molecule produces a copy of itself.

Transcription

The process occurring in the nucleus where $DNA$ produces $RNA$ ($ribonucleic acid$).

Golgi bodies

Also known as the Golgi apparatus, these organelles package, modify, and sort proteins and lipids.

Rough endoplasmic reticulum

A part of the cell that synthesizes proteins, characterized by the presence of ribosomes on its surface.

Smooth endoplasmic reticulum

A part of the cell responsible for the synthesis of lipids.

Lysosome

Commonly called a suicide bag, this organelle contains hydrolytic or digestive enzymes used to break down worn-out organelles.

Autophagy

The process where a lysosome flows toward a worn-out organelle and releases enzymes to break it down.

Autolysis

An abnormal process where the lysosome bursts and releases enzymes that affect functioning organelles, leading to cell death.

Mitochondria

The organelle responsible for energy production in the form of $ATP$, often called the powerhouse of the cell.

$$ATP$$

Standing for adenosine triphosphate, it is the energy currency for the body produced by the mitochondria.

Peroxisome

An organelle that helps to detoxify harmful substances and drugs within the cell.

Ribosome subunits

In eukaryotic cells, ribosomes are made of two subunits: the $60s$ subunit and the $40s$ subunit.

Eukaryotic cells

Cells that possess a well-defined nucleus and nuclear membranes.

Prokaryotic cells

Cells that lack a well-defined nucleus; examples include bacteria and blue-green algae ($cyanobacteria$).

Centrosome

An organelle that specifically assists in the process of cell division.

Cytoskeleton

A network of structures including microtubules, intermediate filaments, and actin filaments that provide structural support and maintain cell shape.