Objectives

4. Name the common elements and compounds required by living organisms.

3. Identify the important organelles of the cell.

1. Enumerate the attributes of living matter.2. Distinguish between prokaryotes and eukaryotes.

Level of Organization

1. Subatomic Paticles- an electron, proton, or neutron; three

major particles of which atoms are composed.

2. Atom- smallest unit of an element that still

remains the properties of that element.

3. Molecule- a unit of two or more atoms of the same

or different elements bonded together.

4. Organelle- any various membraneous sacs or other

compartments inside the cell that separate different metabolic reactions within the cellular space and in time. ribosome

5. Cell- smallest living unit; may live independently or may be part of a

multicellular organism.

red blood cell

6. Tissue- a group of similar cells and intercellular substances

functioning together in a specialized activity.

jellyfish

7. Organ- one or more types of of tissues interacting as a structural,

functioning unit.

brain

8. Organ system- two or more organs whose separate functions are integrated int the performance of a

special task.

• The heart is part of the circulatory system, which carries oxygen and other materials throughout the body. Besides the heart, blood vessels are organs that work in your circulatory system.

heart

9. Multicellular organism- individual composed of specialized,

interdependent cells arrayed in tissues, organs, and other organ system.

Biochemistry asks how the remarkable properties of living organisms arise from the thousands of different lifeless biomolecules.

What is a cell?

Hard to define! Necessary Properties

highly organized and complicated- all organisms are consist of one or more

cells (atoms connect to form molecules, molecules make organelles, and organelles make cells. Cells make up tissue, tissues organized into organs, and organs into organ systems.

Let’s list some of its properties.

uses energy- all organisms acquire and use energy to

perform many kinds of work.

sensitive (interacts with its environment)- plants grow toward light, an animal’s pupils dilate in darkness, amoeba and

paramecia move toward food.

evolutionary adaptation- all organisms interact with the environment and other organisms in ways that

influence their survival to better adapt to their environment. homeostasis

- all organisms maintain ‘relatively’ constant internal conditions like ion concentration, body fluid, temperature, glucose in the bloodstream, blood pH, blood pressure, etc.

metabolism- ability to change substances into different substances to get energy.

reproduces- heriditary molecules (RNA and DNA) ensures production of offspring similar to

previous generation. mutates and evolves

- long term adaptation, new forms of life are formed from life itself

The Cell

All living organisms on earth are made of cells except viruses. The smallest unit that is capable of life.

one-celled organism, Bacteriamulticellur organism, Human

(at least 1014 cells)

There are many different types of cells that are usually highly specialized. The differences could be according to shape and function.

All cells are relatively small. They vary in length from 2 m to 30 m.

• Nucleoid region contains the DNA

• Contain ribosomes (no membrane) to make proteins in their cytoplasm

• Cell membrane and cell wall

Contain organelles such as a nucleus surrounded by membranes

Eukaryotic Cell (Animal)

Most living organisms

Contain 3 basic cell structures:• Nucleus• Cell Membrane• Cytoplasm with organelles

“Typical” Animal Cell

Eukaryotic Cell (Plant)

• Nucleus• Cell Membrane• Cytoplasm with

organelles

Contain 3 basic cell structures:

“Typical” Plant Cell

Functions of Organelles

Cell Membrane

Double membrane surrounding the chromosomes and the nucleolus. Pores allow specific communication with the cytoplasm. The nucleolus is a site for synthesis of RNA making up the ribosome

A lipid/protein/carbohydrate complex, providing a barrier and containing transport and signaling systems. (Serves as security guards or gate keeprs. Decides what can enter or leaves the cell. It lets in useful substances and lets out waste.)

Nucleus

(Serves as the control center. All the activities inside the cell are controlled by instructions which comes from the nucleus.)

Cell wallPlants have a rigid cell wall in addition to their cell membranesCytoplasmenclosed by the plasma membrane, liquid portion called cytosol and it houses the membranous organelles.

Surrounded by a double membrane with a series of foldscalled cristae. Functions in energy production through metabolism. Contains its own DNA, and is believed to have originated as a captured bacterium.

Mitochondrion

(Serves as the power house of the cell. The mitochondira releases energy from food.)

Chloroplasts (plastids)Surrounded by a double membrane, containing stacked thylakoid membranes. Responsible for photosynthesis, the trapping of light energy for the synthesis of sugars. Contains DNA, and like mitochondria is believed to have originated as a captured bacterium.

Endoplasmic reticulum (RER)A network of interconnected membranes forming channels within the cell. Covered with ribosomes (causing the "rough" appearance) which are in the process of synthesizing proteins for secretion or localization in membranes.(Serves as the construction team of the cell.)

A series of stacked membranes. Vesicles (small membrane surrounded bags) carry materials from the RER to the Golgi apparatus. Vesicles move between the stacks while the proteins are "processed" to a mature form. Vesicles then carry newly formed membrane and secreted proteins to their final destinations including secretion or membrane localization.

Golgi body

(Serves as the assembly and storage point of the cell. Some of the substances made in the cells are assembled and stored in the Golgi body.)

A membrane bound organelle that is responsible for degrading proteins and membranes in the cell, and also helps degrade materials ingested by the cell.

Lysosymes

(Serves as the waste disposal unit of the cell. The lysozomes eat up waste materials and old worn out parts of the cell.)

Membrane surrounded "bags" that contain water and storage materials in plants.

Vacuoles

Peroxisomes or MicrobodiesProduce and degrade hydrogen peroxide, a toxic compound that can be produced during metabolism.

Arrays of protein filaments in the cytosol. Gives the cell its shape and provides basis for movement. E.g. microtubules and microfilaments.

Cytoskeleton

Assignment

Purpose: To compare the structure and function of cells with a familiar system.

DIRECTIONS: You will create an analogy (comparison) for a cell using a factory.

Your analogy will include a (1) drawing or model where you label each part of the city/house/body/station and its corresponding cell part (organelle), and a (2) written description of each city/house/body/station part and how it is similar to its corresponding organelle.

Elements of Life

Up to 99+% of the human body is made of the elements C (9.5%), H (25.2%), O (63%) and N (1.4%).

Only 31 chemical elements occur naturally in plants and animals.

Biomolecules in Cells

Bio-molecules Just like cells are building blocks of tissues likewise molecules are

building blocks of cells. Animal and plant cells contain approximately 10, 000 kinds of

molecules (bio-molecules) Water constitutes 65-85% of cells content by weight.

Ions like Na+, K+ and Ca+ may account for another 1% Almost all other kinds of bio-molecules are organic (C, H, N, O, P,

S)

Infinite variety of molecules contain C. Most bio-molecules considered to be derived from hydrocarbons. The chemical properties of organic bio-molecules are determined

by their functional groups. Most bio-molecules have more than one.

Water Molecular Structure of water

Properties of water Water as solvent Water’s thermal properties Surface tension Transparency

Major Classes of small Bio-molecules 1. Amino

acids: • Building blocks of proteins. • 20 commonly occurring.• Contains amino group and carboxyl

group function groups (behavioral properties)

• R Group (side chains) determines the chemical properties of each amino acids.

• Also determines how the protein folds and its biological function.

• Individual amino acids in protein connected by peptide bond.

• Functions as transport proteins,

structural proteins, enzymes, antibodies, cell receptors.

Sugars Carbohydrates most abundant organic molecule found in nature. Initially synthesized in plants from a complex series of reactions involving photosynthesis. Basic unit is monosaccharides. Monosaccharides can form larger molecules e.g.

glycogen, plant starch or cellulose.

Functions Store energy in the form of starch (photosynthesis in

plants) or glycogen (in animals and humans). Provide energy through metabolism pathways and

cycles. Supply carbon for synthesis of other compounds. Form structural components in cells and tissues. Intercellular communications

Fatty acids Are monocarboxylic acid contains even number C atoms Two types: saturated (C-C sb) and unsaturated (C-C db) Fatty acids are components of several lipid molecules. E,g. of lipids are triacylglycerol, streiods (cholestrol, sex

hormones), fat soluble vitamins.

Functions Storage of energy in the form of fat Membrane structures Insulation (thermal blanket) Synthesis of hormones