Cell Biology Study Guide

What are the 3 parts of the Cell Principle?

1. All living organisms are composed of one or more cells. 2. A cell is the basic structural and functional unit of living organisms. 3. All cells arise from pre-existing cells.

What is a macromolecule?

A macromolecule is a molecule with very large number of atoms.

Why do you think antibiotics are an effective medication to fight against bacterial infections?

Antibiotics are medicines that fight infections caused by bacteria in humans and animals by either killing the bacteria or making it difficult for the bacteria to grow and multiply.

What is the difference between plant, animal, and bacterial cells?

Because bacteria are prokaryotic, they do not have a nucleus and no membrane-bound organelles. In contrast, plants and animals are made up of eukaryotic cells, which means they have a nucleus and membrane-bound organelles like mitochondria or Golgi apparatus.

What happens to the surface area to volume ratio as the size of the cell increases?

Cell growth causes the surface area to volume ratio to decrease. This is because, as a cell grows, the volume of the cell (its internal contents) increases faster than its surface area (its cell membrane).

Living things have to be able to gain and use energy. What organelles (more than 1) are used when plants obtain and use power? Explain your answer.

Chloroplasts are the food producers of the cell. The organelles are only found in plant cells and some protists such as algae. Animal cells do not have chloroplasts. Chloroplasts work to convert light energy of the Sun into sugars that can be used by cells.

What is the difference between diffusion and osmosis?

Diffusion can occur in any medium, whether it is liquid, solid, or gas. Osmosis occurs only in a liquid medium. Diffusion does not require a semipermeable membrane. Osmosis requires a semipermeable membrane.

What is diffusion?

Diffusion is the movement of molecules of individual molecules of a substance through a semipermeable barrier from an area of higher concentration to an area of lower concentration.

T/F. All cells have a cell membrane and cytoplasm.

False

Define homeostasis and give an example.

Homeostasis is the ability to maintain internal stability in an organism in response to the environmental changes.

What would be the result if the mitochondria were not functioning properly in a muscle cell?

If your mitochondria are not working properly then you are less able to convert food into ATP. For cells that require a lot of ATP, for example your muscles, this is a problem and they may become weaker and get tired faster.

What is the structure in plant cells that turns light energy into glucose (sugar)?

In a plant cell, chloroplast makes sugar during the process of photosynthesis converting light energy into chemical energy stored in glucose.

Be able to identify the following parts of the cell and describe its functions:

Mitochondria Nucleus Golgi apparatus/body Lysosomes Vacuoles Endoplasmic Reticulum Ribosomes Cytoplasm Cell membrane Cell wall Chloroplast

What is the difference between a prokaryote and a eukaryote?

Prokaryotes are always unicellular, while eukaryotes are often multi-celled organisms.

Why must a cell have a high surface area to volume ratio to remain efficient?

Smaller single-celled organisms have a high surface area to volume ratio, which allows them to rely on oxygen and material diffusing into the cell (and wastes diffusing out) in order to survive. The higher the surface area to volume ratio they have, the more effective this process can be.

What are the 4 types of macromolecules?

The 4 types are lipids, proteins, carbohydrates, and nucleic acids.

Fill in the blanks.

The cell membrane is made mainly of phospholipids and protein.

The cell membrane can be described as a selective barrier. What does that mean?

The cell membrane is selective on what it lets in and out of the cell.

Which structure separates the cell's internal environment from the external environment?

The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment. The cell membrane consists of a semi-permeable lipid bilayer. The cell membrane regulates the transport of materials entering and exiting the cell.

What are the factors that lead to a molecule being able to pass through the membrane without a protein?

The factors that lead to a molecule being able to pass through the membrane without a protein would be if it has molecular size, charge, or temperature/concentration.

What are the functions of these molecules in the membrane?

The functions of these molecules in the membrane are that it allows the membrane to be semipermeable.

Where is the location of cellular respiration, which leads to the production of molecular energy for the cell (ATP)?

The location of cellular respiration is the mitochondria and cytoplasm and it leads to the production of molecular energy for the cell (ATP).

In the movement of the sperm cell, there is a lot of ATP used. What organelle is therefore most present in the flagellum on a sperm cell?

The midpiece of the sperm is packed with mitochondria. Mitochondria are organelles in cells that produce energy. Sperm use the energy in the midpiece to move.

What are the molecular building blocks that make up the cell membrane?

The molecular building blocks that make up the cell membrane are phospholipids.

Which two organelles do plants have that animal cells do not? Explain why plants need these organelles and animals do not.

The plant cells have cell wall, plastids, chloroplasts. These organelles are not present in animal cells. Chloroplasts are used to conduct photosynthesis in plant. Animals don't need to use photosynthesis to gain energy.

What structure do eukaryotic cells have that prokaryotic cells do not have?

The primary difference between prokaryotic and eukaryotic cells is that a nucleus and other membrane-bound organelles are only present in eukaryotic cells.

What are cells?

The smallest unit that can live on its own and that makes up all living organisms and the tissues of the body.

How are these molecules arranged in the cell membrane?

These molecules are arranged in a bilayer in the cell membrane.

T/F. All cells have particular structures that perform specific functions.

True

T/F. Every cell is surrounded by a membrane that serves as a barrier between the cell and its environment

True

What is the difference between single-celled and multicellular organisms?

Unicellular organisms are made up of only one cell that carries out all of the functions needed by the organism, while multicellular organisms use many different cells to function.