Parts of a Cell: Plants and Animals

Plant cells are characterized by a thick cell wall and small bodies within the cytoplasm called chloroplasts, which give the green colour to the plants. These tiny structures are the primary food factory for all living things on Earth. Photosynthesis within the chloroplast is also responsible for producing the oxygen in the air you breathe.

Both animal and plant cells have some similar structural elements. Animal and plant cells have a cell membrane that surrounds the cell. This allows for the cell to exert control, in most cases, over what can penetrate the cell and what cannot.

Cell Membrane The cell is surrounded by a flexible double-layered cell membrane. The function of the cell membrane is both to support the cell and to allow some substances to enter while keeping others out. Because of this ability, the cell membrane is called a “semi-permeable membrane.”

Nucleus The nucleus is the large control centre of a cell, directing all of the cell's activities. Chromosomes that contain your DNA are stored in this organelle. The nucleus is separated from the rest of the cell by the nuclear membrane.

DNA Chromatin is a “thread-like” material inside the nucleus. This material contains genetic information called DNA (deoxyribonucleic acid), a substance that chromosomes are composed of that makes up the genetic code.

Mitochondria The mitochondria is sometimes referred to as the powerhouse of the cell. Mitochondria are largely responsible for providing the cell with energy from glucose (sugar) through a process called cellular respiration.

Endoplasmic Reticulum The endoplasmic reticulum is a three-dimensional network of branching tubes and pockets. It extends throughout the cytoplasm from the nuclear membrane. These fluid-filled tubes transport materials, such as proteins, through the cell.

Ribosomes Found on the endoplasmic reticulum or free in the cytoplasm. Proteins are made in this organelle.

Golgi Bodies Golgi bodies collect and process materials to be removed from the cell. They also make and secrete mucus. Cells that secrete a lot of mucus, such as cells lining the intestine, have many Golgi bodies.

Cytoplasm All the organelles inside the cell are suspended in the cytoplasm. The cytoplasm is mostly water, but it also contains many other substances that the cell stores until they are needed. Many chemical reactions take place within the cytoplasm.

Found Only In Plant Cells Chloroplast Vacuole Cell Wall

Chloroplasts Contain chlorophyll and give leaves their green colour. Absorb light energy which is used in photosynthesis light energy Carbon dioxide + water → glucose + oxygen

Cell Wall Just outside the cell membrane Provides support and protection from physical injury

Vacuole Plants usually have one large vacuole which takes up most of the space inside the cell. When full of water, turgor pressure keeps the cells plump which keeps the plant’s stems and leaves firm.

Bacteria Cell

Endosymbiotic Theory