Cell Organelles-Class notes

The Characteristics of Life

  1. made up of one or more cells

  2. displays organisation and structure

  3. grows and develops

  4. reproduces

  5. responds to stimuli

  6. requires energy

  7. maintains homeostasis

  8. adaptations evolve over time

Structure of Cells

Two types of Cells

Prokaryotes

  • bacteria

  • unicellular

  • oldest living thing

  • do not contain nuclei

  • small simple cells

Eukaryotes

  • plants, animals, fungi, and protists

  • unicellular or multicellular

  • contain nuclei

  • larger

  • many organelles with own membrane

  • highly specialised for their function

Organelles

All types of organelles

  • cell wall

  • cell membrane

  • cytoplasm

  • ribosomes

  • DNA

  • nucleus

  • rough endoplomic reticulum

  • gogli apparatus

  • vacoule

  • lysosome

  • Mitochondria

  • chloroplast

cell wall

  • outermost layer in plants, fungi, and prokaryotes

  • supports and protects the cell

cell membrane

  • controls materials entering and leaving the cell

  • supports and helps contain the cell and its form

cytoplasm

  • gel like substance that fills the cell

  • cyto=cell

  • site of many chemical reactions

ribosome

  • where proteins are assembled

  • proteins are assembled and necessary for all chemical reactions in the cell(enzymes)

DNA

  • includes instructions for most of the cells work, and gives everyone the job they have to do for the cell

Nucleus

  • contains most of the cells DNA

Rough Endoplasmic Reticulum(ER)

  • has ribosomes on its surface so it is involved in protein sythesis and transport of those proteins

Gogli Apparatus

  • warehouse of the cell

  • modifies, sorts, and packages proteins and materials to be ‘shipped out’(secreted)

  • the packages it secrets are called vesicles

Vacuole

  • stores materials such as salt, water and proteins

  • large central vacouls are located in plant cells

Lysosome

  • lys=break down

  • small vesicles with digestive proteins

  • work as a ‘clean up crew’

  • break down junk

  • white blood cells(wbc) have many

Mitochondria

  • power house of the cell

  • converts food into energy

  • have their own DNA

Chloroplast

  • Captures the suns energy and coverts it into chemical energy through photosynthesis

  • has chlorophyll to process the suns energy

  • acts like a solar power plant

  • not in the roots as these do not get sunlight

Difference of Plant and Animal cells

Plant

  • cell walls

  • chloroplasts - contain chlorophyll

  • larger

  • rarely have lysosomes

Animal

  • no cell wall

  • no chloroplast

  • some have small vacuoles

  • smaller

  • have lysosomes

Characteristics of Life

Living organisms are characterized by being made up of one or more cells, displaying organization and structure, growing and developing, reproducing, responding to stimuli, requiring energy, maintaining homeostasis, and evolving adaptations over time.

Structure of Cells

Cells can be divided into two main types: prokaryotes and eukaryotes. Prokaryotes are unicellular organisms, such as bacteria, that are considered the oldest living things. They do not contain nuclei and are small, simple cells. In contrast, eukaryotes include organisms such as plants, animals, fungi, and protists. They can be either unicellular or multicellular and contain nuclei, making them larger and more complex with many specialized organelles, each enclosed in its own membrane.

Organelles

Various organelles play critical roles in cell function. The cell wall, found in plants, fungi, and prokaryotes, serves as the outermost layer, supporting and protecting the cell. The cell membrane controls the materials entering and leaving the cell while maintaining its shape. The cytoplasm, a gel-like substance filling the cell, is where many chemical reactions occur. Ribosomes are sites where proteins are assembled, which are vital for all chemical reactions within the cell, including enzyme production. The DNA contains the instructions essential for cellular activities and dictates the roles of different cell components. The nucleus houses most of the cell's DNA.

The rough endoplasmic reticulum (ER), dotted with ribosomes, is involved in protein synthesis and the transport of proteins. The Golgi apparatus acts as the cell's warehouse, modifying, sorting, and packaging proteins and materials for secretion, referred to as vesicles. Vacuoles store materials such as salt, water, and proteins, with large central vacuoles commonly found in plant cells. Lysosomes function as the cell's cleanup crew, comprising small vesicles filled with digestive proteins that break down waste. Mitochondria, often described as the powerhouse of the cell, convert food into energy and contain their own DNA. Chloroplasts, present in plants but absent in roots, capture sunlight and convert it into chemical energy through photosynthesis.

Differences Between Plant and Animal Cells

Plant cells are distinguished by the presence of cell walls and chloroplasts, which contain chlorophyll. They are generally larger than animal cells and rarely have lysosomes. Conversely, animal cells lack cell walls and chloroplasts, may have small vacuoles, are smaller in size, and possess lysosomes.