Cell Biology Chapter 10

Cells and Living Things

• Living things are made up of cells, which are the basic, functional units of life.
• All living things exhibit certain characteristics, including:
  • Growth, which occurs when cells increase in number and new cells replace old ones.
  • Movement, which involves a change in position, shape, or location.
  • Response to stimuli, which can be internal or external.
  • Reproduction, which involves producing more of the same kind.

The Compound Light Microscope

• The microscope has several parts, including:
  • Eyepiece
  • Body tube (barrel)
  • Coarse adjustment knob
  • Fine adjustment knob
  • Objective lenses
  • Revolving nosepiece
  • Stage
  • Iris diaphragm
  • Light source
  • Base
  • Arm
• Total magnification is calculated by multiplying the power of the objective lens and the power of the eyepiece lens.

Cell Theory

• The cell is the basic unit of life.
• All living things are made up of one or more cells.
• All cells come from other living cells.

Cell Organelles

• Cell membrane: found in both plant and animal cells, surrounds and protects the cell contents, and controls the movement of materials in and out of the cell.
• Cytoplasm: found in both plant and animal cells, is a jelly-like fluid that organelles float in, and helps move materials like food to different parts of the cell.
• Cell wall: found only in plant cells, is a tough, rigid structure that gives plant cells their box-like shape, and is made mostly of cellulose.
• Nucleus: found in both plant and animal cells, is a large, round structure that contains chromosomes, and is the "control centre" of the cell.
• Vacuole: found in both plant and animal cells, is a balloon-like space in the cytoplasm that stores materials that can't be used right away, and is larger and fewer in plant cells, and smaller and more numerous in animal cells.
• Mitochondrion: found in both plant and animal cells, is an oval, bean-like structure that produces energy by breaking down food particles.
• Chloroplast: found only in plant cells, is a green structure that contains chlorophyll, and captures the sun's energy for photosynthesis.

Plant vs. Animal Cells

• Cell wall: present in plant cells, but not in animal cells.
• Vacuole: larger and fewer in plant cells, and smaller and more numerous in animal cells.

Dividing Cells

• Cell division is necessary for growth and reproduction.
• Cell division occurs through mitosis, which occurs in body cells (somatic cells) but not in sex cells (egg and sperm cells).
• Bacteria cells reproduce through mitosis.

Energy for Cells

• Cells need energy for all life processes.
• Energy is stored in food, specifically glucose (a type of sugar).
• Cells release energy through cellular respiration, which takes place in the mitochondrion and converts energy into another form.
• Oxygen is necessary for cellular respiration, and carbon dioxide and water vapor are waste gases produced.