Unit 2 Human Biology and Health - A1 Cells

Vocabulary flashcards covering the structure and function of cell organelles and specialized human cell types as described in Unit 2: Human Biology and Health.

Organelles

Tiny structures inside a cell that have special jobs to help the cell work properly.

Cell Membrane

A soft, flexible, selectively semi-permeable layer that surrounds the cell and controls the movement of substances like oxygen, glucose, and waste (carbon dioxide) in and out of the cell.

Nucleus

The 'control centre' of the cell that holds the DNA and regulates the activities of the cell by controlling gene expression.

DNA

The genetic material housed in the nucleus that is packed into structures called chromosomes.

Chromosomes

Structures made up of DNA found in the nucleus; human cells contain $23$ pairs.

Genes

Smaller parts of chromosomes that provide instructions for making specific proteins, which determine a person's traits.

Ribosomes

Smallest parts of the cell, composed of RNA and proteins, responsible for protein synthesis.

Protein Synthesis

The process where ribosomes read instructions from messenger RNA (mRNA) and join amino acids in the correct order to build proteins.

Mitochondria

Often called the 'powerhouses' of the cell, these bean-shaped organelles release energy through cellular respiration.

Cellular Respiration

A process occurring in the mitochondria that uses enzymes to break down glucose to produce $ATP$, the main energy source for the cell.

ATP

The primary energy source for the cell that powers activities such as muscle movement and protein production.

Epithelial Cells

Cells that form the covering or lining of all internal and external body surfaces, including skin and the lining of the gut.

Keratinocytes

A specific type of epithelial cell found in the skin.

Enterocytes

A specific type of epithelial cell that lines the gut.

Neurons (Nerve Cells)

Cells specialized for communication through electrical and chemical signals, consisting of dendrites, an axon, and a cell body.

Dendrites

Branch-like extensions of a neuron that receive incoming signals from other neurons.

Axon

A long, slender projection of a neuron that transmits signals away from the cell body.

Myelin Sheath

An insulating layer that often covers the axon to facilitate signal transmission.

Skeletal Muscle Cells

Long, cylindrical, and multinucleated cells that control voluntary movement.

Cardiac Muscle Cells

Striated, branched cells found exclusively in the heart.

Smooth Muscle Cells

Spindle-shaped cells with a single nucleus responsible for involuntary movement, located in areas like the gut.

Erythrocytes (Red Blood Cells)

Cells that carry oxygen; they feature a biconcave shape and lack a nucleus to maximize haemoglobin capacity for oxygen transport.

Leukocytes (White Blood Cells)

Cells containing a nucleus that are responsible for the body's immune response.

Thrombocytes (Platelets)

Fragments of larger cells that are responsible for the process of blood clotting.

Sperm Cells

Male gametes consisting of a head with a nucleus, a midpiece packed with mitochondria for energy, and a tail (flagellum) for movement.

Ova (Egg Cells)

Female gametes that contain a nucleus with half the chromosomes and cytoplasm to provide nutrients for the early embryo.

Squamous

Flat-shaped epithelial cells specialized based on location and function.

Cuboidal

Cube-shaped epithelial cells.

Columnar

Tall, column-shaped epithelial cells.

Fluid Mosaic Model

A detailed model used to describe the arrangement and movement of the molecules that make up a cell surface membrane.

Epithelial Cells

Cells that form the covering or lining of all internal and external body surfaces, including skin and the lining of the gut. Epithelial cells can be categorized into different shapes:

Types of Epithelial Cells

1. Squamous: Flat-shaped epithelial cells. 2. Cuboidal: Cube-shaped epithelial cells. 3. Columnar: Tall, column-shaped epithelial cells.

Muscle Cells

Cells specialized for contraction and movement. There are three main types of muscle cells:

Skeletal Muscle Cells

Long, cylindrical, and multinucleated cells that control voluntary movement.

Cardiac Muscle Cells

Striated, branched cells found exclusively in the heart.

Smooth Muscle Cells

Spindle-shaped cells with a single nucleus responsible for involuntary movement, located in areas like the gut.

Erythrocytes (Red Blood Cells)

Cells that carry oxygen; they feature a biconcave shape and lack a nucleus to maximize haemoglobin capacity for oxygen transport.

Leukocytes (White Blood Cells)

Cells containing a nucleus that are responsible for the body's immune response.

Thrombocytes (Platelets)

Fragments of larger cells that are responsible for the process of blood clotting.

Additional Blood Cells

Other blood components include various types of leukocytes, such as lymphocytes, neutrophils, monocytes, eosinophils, and basophils, each with specific roles in immunity.

Erythrocytes (Red Blood Cells)

Cells that carry oxygen; they feature a biconcave shape and lack a nucleus to maximize haemoglobin capacity for oxygen transport.

Leukocytes (White Blood Cells)

Cells containing a nucleus that are responsible for the body's immune response.

Thrombocytes (Platelets)

Fragments of larger cells that are responsible for the process of blood clotting.

Additional Blood Cells

Other blood components include various types of leukocytes, such as lymphocytes, neutrophils, monocytes, eosinophils, and basophils, each with specific roles in immunity.