Stage 2 Biology - Cells as a Basis of Life

What is the cell theory?

What is the cell theory?

The cell theory states that all living organisms are composed of cells, cells are the basic unit of structure and function in living organisms, and all cells come from pre-existing cells.

What is the function of the cell membrane?

The cell membrane regulates the passage of substances in and out of the cell, maintaining homeostasis and protecting the cell.

What is the purpose of the double layer of lipids surrounding the cell membrane?

The double layer of lipids, known as the phospholipid bilayer, acts as a barrier to control the movement of substances in and out of the cell.

purpose of integral membrane proteins

Purpose of Integral Membrane Proteins: Integral membrane proteins are embedded in cell membranes and serve various functions such as transport of molecules, cell signaling, cell adhesion, and enzymatic activity. They help maintain cell structure, regulate cell processes, and facilitate communication between cells.

purpose the peripheral membrane protein

Purpose of Peripheral Membrane Proteins: Peripheral membrane proteins are involved in various functions such as cell signaling, transport of molecules, and structural support at the cell membrane. They do not penetrate the lipid bilayer but rather associate with the membrane temporarily.

difference between peripheral membrane proteins and integral membrane proteins

• Peripheral Membrane Proteins:

  • Found on the surface of the membrane.

  • Easily detachable.

  • Do not span the entire membrane.

• Integral Membrane Proteins:

  • Embedded within the membrane.

  • Not easily detachable.

  • Span the entire membrane.

What is diffusion?

Diffusion is the movement of particles from an area of high concentration to an area of low concentration, resulting in equal distribution.

What is osmosis?

Osmosis is the movement of water molecules across a selectively permeable membrane from an area of high water concentration to an area of low water concentration.

What is endocytosis?

Endocytosis is a cellular process in which cells absorb molecules by engulfing them with their cell membrane.

exocytosis

Question: What is exocytosis?

Answer: Exocytosis is the process by which cells release substances outside of the cell by fusing vesicles with the cell membrane.

channel proteins

Channel Proteins

Channel proteins are integral membrane proteins that form channels across the cell membrane, allowing the passage of specific ions or molecules. They facilitate the transport of substances such as ions, water, and other solutes across biological membranes. Examples include aquaporins for water transport and ion channels like sodium and potassium channels for ion transport.

What is a key difference between prokaryotic and eukaryotic cells?

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have both a nucleus and organelles.

What are autotrophs and heterotrophs?

Autotrophs are organisms that can produce their own food, while heterotrophs rely on other organisms for food.

What is the process by which cells convert glucose into energy using oxygen?

Aerobic respiration.

What is anaerobic respiration?

Anaerobic respiration is the process of producing energy from glucose without the use of oxygen, resulting in the production of lactic acid or ethanol.

What is metabolism?

Metabolism is the process by which your body converts food and drink into energy for essential functions like breathing and digestion.

What are the two main types of metabolic reactions?

Anabolic reactions build molecules, while catabolic reactions break them down for energy.

What is the primary function of ATP energy in a cell?

ATP energy is used as a source of energy for various cellular processes, such as muscle contraction, active transport, and chemical reactions.

Where does cellular respiration occur in eukaryotic cells?

Mitochondria.

What is mitosis?

Mitosis is the process of cell division in which a single cell divides into two identical daughter cells.

What is the process by which a diploid cell divides to produce four haploid cells?

Meiosis

What is a key difference between mitosis and meiosis in terms of chromosome number?

• In mitosis, the daughter cells have the same number of chromosomes as the parent cell,

• while in meiosis, the daughter cells have half the number of chromosomes.

What is interphase?

Interphase is the longest phase of the cell cycle where the cell grows, carries out normal functions, and prepares for cell division.

describe prophase

Prophase is the first stage of mitosis where chromatin condenses into chromosomes, the nuclear envelope breaks down, and the spindle fibers begin to form.

What happens in metaphase during cell division?

In metaphase, chromosomes align at the cell's equator, ready to be separated into two daughter cells during mitosis or meiosis.

what happens in anaphase

In anaphase, sister chromatids separate and move towards opposite poles of the cell, pulled by spindle fibers.

What happens in telophase during cell division?

In telophase, the chromosomes reach the opposite poles of the cell, the nuclear envelope reforms, and the chromosomes begin to decondense.

What is the final stage of cell division?

Cytokinesis, where the cytoplasm divides to form two separate daughter cells.