Biology 30

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unit 3.1

cell theory

principles of cell theory

states that all living organisms are made of cells, cells are the basic unit of life, and all cells come from pre-existing cells.

the cell theory and the concept of a cell

a unifying concept in science

cells are the basic unit of life

scientists who contributed to cell theory

include Robert Hooke, Anton van Leeuwenhoek, Matthias Schleiden, Theodor Schwann, and Rudolf Virchow.

Hooke

was the first to observe and describe cells using a microscope in 1665. He looked at cork cells

Leeuwenhoek

observed bacteria using lenses he made through a microscope which allowed him to see in greater detail in 1674. father of microbiology

Schleiden

he was the first to note that plants are made of cells in 1838.

Schwann

concluded that all living things are made of cells in 1839. he looked at animal cells and tissues

Virchow

he proposed that all cells come from other cells in 1855

why is cell theory important?

Cell theory gives us a better understanding of what life is

it gives us knowledge for more research

it is a unifying concept of biology

What is a eukaryotic cell?

Cells that contain a nucleus. Have membrane bound organelles. Can be multi or unicellular. Examples. Animal, plant, fungi, and protist cells.

What is a prokaryotic cell?

No nucleus DNA is stored within the cytoplasm. No complex organelles. Example bacteria cell.

Animal Cell.

Specialized cells found in animals, such as muscle, bone and nerve cells.

Plant Cell.

Cells found in plants, which includes a cell wall and chloroplast.

Fungal Cell.

Cells that make up organisms like mushrooms and yeast.

Protist Cell.

Single celled organisms like a mebos, paramecia and algae

Bacteria Cell.

Single celled organisms.

All cells contain what?

Cytoplasm, DNA and a cell membrane.

What's inside of a eukaryotic cell?

Nucleus, DNA, cytoplasm, cell membrane and complex organelles.

What's inside of a prokaryotic cell?

DNA, cell membrane, and cytoplasm.

What's inside of an animal cell?

Nucleolus Chromosomes, Nucleus, Rough ER, Smooth ER, Ribosomes, Lysosome, Golgi apparatus, Vesicles, cell membrane. Cytoplasm, Microtubules, Mitochondria, Cilia, Nuclear membrane, Vacuole.

What's inside of a plant cell?

Mitochondria, Vacuole, Cell membrane, Golgi apparatus, Chloroplasts, smooth ER, rough ER, nucleus, nucleolus, Cell wall, ribosome. DNA.

3.2.

Cell organelles.

Cytoskeleton.

Supports and shapes the cell network of proteins that's constantly changing to meet the cell's needs.

Nucleus.

Storehouse of genetic information, dense region were tiny organelles that make proteins are assembled.

ER.

Interconnected network of thin folded membranes. Many processes, including production of proteins and lipids.

Rough ER.

Produces proteins.

Smooth ER.

Produces lipids and breaks down alcohol in the liver.

Ribosome

Tiny organelles that link amino acids together to form proteins.

Golgi apparatus.

Processes, sorts and delivers proteins through vesicles. Some proteins are stored in Golgi apparatus for later use.

Vesicle.

Buds off of the Golgi apparatus carrying complete proteins out of the cells. Transports materials from cell to cell.

Mitochondria.

Powerhouse of the cell generates energy or, ATP for the cell from foods (glucose).

Vacuole.

Temporarily stores materials like waste and fluids.

Lysosome.

Lysosome digest and recycled foreign materials or worn out parts.

Centrioles.

Centrioles divide DNA during cell division. They look like licorice.

Cell wall.

Cell walls shape and support individual cells and entire organisms.

Chloroplast.

Chloroplasts converts solar energy into chemical energy through photosynthesis.

Cytoskeleton.

Network of proteins within a cell that provides shape and mechanical support. Helps organize and move internal components like organelles.

3 parts of the cytoskeleton

Microfilaments. Intermediate filaments.And microtubules.

Microfilaments.

Microfilaments are the thinest component made of protein actin. They are involved in cell movement and muscle contraction. They help provide the cell with rigidity and shape.

Intermediate filaments.

these are the most durable of the three components provide tensile strength and anchoring the cells nucleus and other organelles in place their components vary depending on cell type

Microtubules.

the thickest filament and are crucial part of the cells delivery process. They are rigid hollow tubes in eukaryotic cells, which help with transporting materials in the cell.

Cytoskeleton.

The cytoskeleton supports and shapes the cell, helps position and transport organelles, provide strength, assists in cell division, and aids in cell movement.

Which organelles are involved in making and processing proteins?

Ribosomes link amino acids to form proteins.

Vesicles hold complete proteins and bring them out of the cell.

The Golgi apparatus sorts, processes and delivers proteins and sometimes stores them.

The nucleus holds Instructions for protein synthesis.

3.3.

The cell membrane.

The membrane is described as a fluid mosaic model.

Fluid stands for flexibility.

mosaic means it has different sizes of pieces in it.

Cell membrane functions.

The sun membrane has two functions. The cell membrane forms a boundary between inside and outside of the cell, and it controls passage of materials.

What could need to get inside of a cell?

glucose water oxygen and amino acids

Cell membrane diagram.

A cell membrane diagram consists of proteins, protein channels, carbohydrate chains cholesterol and phospholipids.

How many layers of phospholipids does a cell membrane have?

2.

Phospholipid.

a phospholipid is a molecule that has a polar head and non polar tails.

what are phospholipid heads and tails made of

A Phospholipid headers made out of phosphate molecules in glycerol. And a phospholipid tail is made of fatty acids.

Different temperatures of a cell membrane.

If it is warm, it will spread, if it is cold it will tighten.

A cell is kind of like

A big water balloon.

Does the cell membrane let all materials through?

No, it is selectively permeable. Which means it only allows certain materials through.

What determines what crosses through the membrane?

Size, polarity, and concentration. ex. Too large, polar, and moving up or down in concentration.

Phospholipid structure.

A phospholipid has a hydrophilic water attracting phosphate head (allows them to create hydrogen bonds) and two hydrophobic water repelling fatty acid tails.

Receptors.

membrane and intracellular receptors

Receptors bind with ligands(tiny molecules) and change shape.

Membrane receptor.

Membrane receptors are proteins embedded in the cell membrane that act as receivers for external signals, converting them into internal responses.

intracellular receptors

Intercellular receptors are located inside of the cell, inside the cytoplasm or nucleus. They bind to small molecules that pass through the cell membrane. They then enter the nucleus to regulate gene expression by binding into specific DNA sequences.

3.4.

Diffusion and osmosis.

Why do materials move across membranes?

Because of concentration difference.

Passive transport.

Passive transport does not require energy input from a cell.

Types of passive transport.

Diffusion and osmosis.

Diffusion.

High to low concentration.

Osmosis.

Diffusion of water only. Across a semi permeable membrane.

Three types of solutions.

Isotonic, hypertonic, and hypotonic.

Isotonic.

Cell remains the same example, 98% H20 2% solutes.

Hypertonic.

loses water quicker than it gains water example 95% H20 5% solutes

Hypotonic.

Games water quicker than it loses it. Example 99% H20 1% solutes.

Distilled.

100% H2O.

Needed by mitochondria.

Glucose, amino acids, fatty acids, minerals, vitamins, sodium.

Facilitated diffusion.

Diffusion through transport proteins.

What can easily diffuse?

Small lipids and other non polar molecules. Example carbon dioxide and oxygen.

What can't easily diffuse?

Large molecules and other polar molecules. example glucose ions proteins and hydrogen bonds

3.5.

Active transport. Endocytosis and exocytosis.

Protein pumps.

Protein pumps move materials against a concentration gradient.

Active transport.

Movement of a substance from a lower concentration to a region of higher concentration by the use of transport proteins inside the cell membrane and chemical energy.

Endocytosis and exocytosis.

Both transport materials across the membrane in vesicles. cells can use energy to transport large molecules or large amounts of molecules without crossing the cell membrane.

Endocytosis.

Engulfs large groups of molecules in a membrane. After the vesicle makes its way inside, a lysosome breaks down the contents if needed and then recycles the vesicle.

Exocytosis.

Exocytosis is the opposite of endocytosis. It is the release of a substance out of the cell by the fusion of a vesicle with the membrane of vesicle forms around materials to be sent out of the cell. The vesicle then moves towards the cell surface where it fuses with the membrane and let's go of its contents.

Phagocytosis.

Phagocytosis is a type of endocytosis in which the cellular membrane engulfs large particles. It plays a key role in your immune system. White blood cells called macro phages find foreign materials such as bacteria in your body and engulf and destroy them.

5.1.

Cell cycle.

Cell cycle.

Gap 1 synthesis. Gap 2 mitosis.

Gap 1.

Cells grow, carry out normal functions like making proteins with ATP, and replicate their organelles. Cells increase in size and organelles increase in numbers. Length of the stage varies the most depending on cell type. Contains a critical checkpoint.

Synthesis.

DNA duplicates. The cell makes a nuclear copy of its DNA. By the end of the stage, the nucleus contains 2 complete sets.

Gap 2.

Additional cell growth, contains a critical checkpoint. Everything must be in order. (Good cell size, undamaged DNA.)

Mitosis.

Mitosis and cytokinesis make up the mitosis stage. Divides the cell nucleus and its contents, nuclear membrane dissolves duplicated DNA, condenses around proteins and separates, and two new nuclei form. Then cytokinesis divides the cytoplasm.

What grows quicker, volume or surface area?

Volume.

What is the gap 0 stage?

Go stage is the stage where cells are unlikely to divide as they continue to carry out normal functions example liver cells.

What must be coordinated for cell sizes to stay the same as they continue to divide?

Growth and division.

Stages of mitosis.

pmat prophase, metaphase, anaphase telophase then cytokinesis.

Cell size is limited.

Cells must stay small so that materials can move in and out. Volume grows quicker than surface area. If a cell gets too big, it can't move it's nutrients around quick enough.

Cells don't divide at the same rate for three reasons.

Depends on the type of cell, depends how much our body needs it depends on how often we use what needs to divide. Example skin more often and liver takes longer.

5.2.

Mitosis and cytokinesis.

Stages of DNA changing.

DNA double Helix. DNA and histones. Chromatin. Supercoiled DNA. And chromatid.

Chromosome.

a chromosome is a long continuous thread of DNA

Why and when do chromosomes condense?

At the start of mitosis so the DNA can be separated properly. Chromosomes are not condensed during other stages because the cell still needs to access the DNA during those other stages.

How does interphase prepare a cell to divide?

Interface allows the cell to grow duplicate organelles, duplicate DNA. To be able to be separated.

What types of cells does mitosis occur in?

All of the body cells except for ones that produce sperm or eggs.