Animal Cell Structure and Function

• The cell is the basic unit of life.
• The two main types of cells are animal and plant cells.

Plasma Membrane Function (Animal Cells)

• Encloses all cell components
• Regulates substance exchange
• Maintains the cell's internal environment

Plasma Membrane Components

• Proteins
• Phospholipid bilayer

Nucleus Function (Animal Cells)

• Controls all cell activities, including metabolism and characteristics

Nucleus Components

• Nucleolus
• Chromosomes (DNA)
• Nucleoplasm

Cytoplasm Function (Animal Cells)

• Supports internal structure
• Maintains cell shape
• Medium for metabolic activities

Rough Endoplasmic Reticulum (RER) Function

• Synthesizes proteins
• Transports proteins to the Golgi apparatus for modification

RER vs. Smooth Endoplasmic Reticulum (SER)

• RER has ribosomes and synthesizes proteins.
• SER synthesizes lipids and detoxifies harmful substances.

Mitochondria Function

• Generates energy in the form of ATP through cellular respiration

Golgi Apparatus Function

• Modifies, packages, and transports proteins and lipids in vesicles

Centrioles Role (Animal Cells)

• Form spindle fibers during cell division to separate chromosomes

Lysosomes Function

• Digests macromolecules
• Destroys bacteria and viruses
• Breaks down damaged or dead cells

Ribosomes Location

• Cytoplasm
• Attached to the rough endoplasmic reticulum

Ribosomes Function

• Protein synthesis

Organelles Common to Animal and Plant Cells

• Plasma membrane
• Nucleus
• Cytoplasm
• Golgi apparatus
• Mitochondria
• Endoplasmic reticulum
• Ribosomes

Cell Wall Function (Plant Cells)

• Protects from osmotic and mechanical stress
• Helps maintain cell shape

Chloroplasts Function (Plant Cells)

• Converts light energy into chemical energy during photosynthesis

Vacuole Role (Plant Cells)

• Stores water to maintain turgidity
• Excretes unwanted substances

Vacuole Structure (Plant Cells)

• Surrounded by a membrane called the tonoplast
• Contains water, enzymes, ions, and waste products

Plasmodesmata Function (Plant Cells)

• Channels that allow for communication and transport of substances between plant cells

Main Differences Between Animal and Plant Cells

• Plant cells: fixed shape due to the cell wall, chloroplasts for photosynthesis, and larger vacuoles
• Animal cells: do not have a fixed shape, chloroplasts, or large vacuoles

Carbohydrate Storage

• Animal cells: Glycogen

• Plant cells: Starch

• Plant cells do not have centrioles.

• Plant cells have large vacuoles, while animal cells have smaller vacuoles or none at all.

Nucleolus Function

• Production of ribosomal RNA (rRNA)

• Assembly of ribosomes

• Animal cells have an irregular shape.

• Plant cells have a fixed shape due to the presence of the cell wall.

Chlorophyll Function (Plant Cells)

• Absorbs light energy for photosynthesis

Unicellular Organisms Defined

• Organisms that consist of a single cell

• Can perform all living processes within that one cell

• Unicellular organisms can perform all living processes such as respiration, growth, movement, reproduction, feeding, and excretion.

• Amoeba sp. and Paramecium sp. are common examples of unicellular organisms.

• Amoeba sp. can typically be found in freshwaters.

• Paramecium sp. has a shoe-shaped appearance.

Binary Fission (Amoeba sp.)

• Asexual reproduction in which a parent Amoeba cell divides into two identical daughter cells

Binary Fission Process (Amoeba sp.)

• The parent cell's nucleus divides
• Cytoplasm begins to split
• Two new daughter cells are formed

Amoeba sp. Feeding

• Uses pseudopodia (false feet) to extend and engulf food particles
• Food particles are stored in a vacuole for digestion

Amoeba sp. Digestion

• Ingested food is packed into a vacuole
• Lysosomes combine with the vacuole to release digestive enzymes that break down the food
• Digested food particles are absorbed into the cytoplasm after digestion in the vacuole

Amoeba sp. Waste Excretion

• Undigested materials are excreted as waste products through the cell membrane

Lysosomes Role in Amoeba sp. Feeding

• Release enzymes that digest the food inside the vacuole
• Allows nutrients to be absorbed into the cytoplasm

Amoeba sp. Energy Acquisition

• Digests food particles engulfed through phagocytosis
• Food particles are broken down inside the vacuole

Significance of Pseudopodia (Amoeba sp.)

• Allows Amoeba sp. to move and capture food through phagocytosis

Amoeba sp. Reproduction

• Binary fission, an asexual reproduction process

Lysosomes Role in Amoeba sp. Digestion

• Contains digestive enzymes to digest food in the vacuole

Vacuole Purpose (Amoeba sp.)

• Stores ingested food
• Site of digestion

Phagocytosis (Amoeba sp.)

• The process by which Amoeba sp. extends its pseudopodia to engulf food particles

Importance of Binary Fission (Amoeba sp.)

• Allows Amoeba sp. to reproduce and increase its population asexually

Unicellular vs. Multicellular Organisms

• Unicellular organisms consist of only one cell
• Multicellular organisms are made up of multiple specialized cells that perform different functions

Intestinal Epithelial Cells Function

• Have microvilli that enhance nutrient absorption during food digestion

Smooth Muscle Cells Role

• Line organs like the stomach and intestines
• Involved in involuntary muscle movements

Cardiac Muscle Cells Function

• Found in the heart
• Contract involuntarily, producing strong and rhythmic movements

Red Blood Cells and Platelets Characteristic

• Lack a nucleus
• White blood cells have different-shaped nuclei for differentiation

Nerve Cells (Neurons) Role

• Have a myelin sheath that helps transmit electrical impulses faster along the nerve cells

Sperm Cells Function

• Male reproductive cell or gamete
• Produced and stored in the testes for fertilization

Xylem Cells Function (Plants)

• Transporting water and minerals in plants
• Made up of dead cells and lack organelles

Phloem Cells Function (Plants)

• Transporting sucrose and amino acids (products of photosynthesis) throughout the plant

Root Hair Cells Function (Plants)

• Increase surface area for better absorption of water from the environment

Epithelial Tissue

• Lines body surfaces, hollow cavities, and organs
• Involved in protection, secretion, absorption, excretion, diffusion, and sensory reception

Main Types of Epithelial Tissues

• Simple cuboidal
• Simple squamous
• Simple columnar
• Stratified squamous

Muscle Tissue Role

• Generating movement by contracting and relaxing
• Divided into smooth muscle, skeletal muscle, and cardiac muscle

Main Types of Connective Tissue (Humans)

• Cartilage
• Bone
• Adipose tissue
• Blood
• Loose connective tissue
• Fibrous connective tissue

Blood Function (Connective Tissue)

• Composed of plasma and blood cells (red blood cells, white blood cells, and platelets)
• Helps in the transport of oxygen, nutrients, and waste products

Translocation (Plants)

• Movement of sucrose and amino acids (products of photosynthesis) within the plant

Parenchyma Tissue Role (Plants)

• Performs functions such as photosynthesis, storage, and secretion in plants

Collenchyma Tissue Function (Plants)

• Provides support in herbaceous plants
• Has thicker, irregular cell walls

Sclerenchyma Tissue Role (Plants)

• Provides strong support in plants, especially in wood and fibers
• Consists of dead cells with thick cell walls

Mitochondria Function in Different Cell Types

• Abundant in cells like adipose, sperm, and muscle cells
• Needs energy for fat storage, movement, and muscle contraction

Chloroplasts Role in Cells

• Abundant in palisade mesophyll and spongy mesophyll cells
• Maximizes the process of photosynthesis for food production

RER and Golgi Apparatus Importance in Cells

• Abundant in cells like pancreatic, goblet, and liver cells
• Synthesizes and secretes digestive enzymes and proteins

Smooth Endoplasmic Reticulum (SER) Function in Liver Cells

• Detoxifies drugs and toxins

Tay-Sachs Disease

• Caused by a deficiency of an enzyme found in lysosomes
• Leads to the dysfunction of cell processes

Skeletal Muscle Tissue Function

• Involved in voluntary movement
• Striated
• Allows for movement like walking or lifting

Smooth Muscle Tissue vs. Skeletal Muscle

• Smooth muscle tissue is non-striated
• Involved in involuntary, slow contractions like those in the digestive system

Myelin Sheath Function (Nerve Cells)

• Speeds up the transmission of electrical impulses along nerve cells

Xylem Tissue Function (Plants)

• Responsible for the transport of water and minerals from the roots to other parts of the plant

Tissues, Organs, and Systems

• Tissues combine to form organs
• Organs work together in systems to perform specific functions within the organism

Lung Tissue Composition

• Smooth muscle tissue

• Epithelial tissue

• Connective tissue

• Nerve tissue

• There are 11 main organ systems in humans.

• The 11 main organ systems are: Respiratory, Digestive, Blood Circulatory, Lymphatic, Reproductive, Urinary, Endocrine, Integumentary, Muscular, Nervous, and Skeletal systems.

• The two main systems in plants are the shoot system and the root system.

• The shoot system in plants consists of leaves, flowers, stems, fruits, and shoots.

• The root system in plants consists of the roots, which anchor the plant and absorb water and minerals.

• The leaves store starch and are involved in photosynthesis.

• The stem helps keep the plant upright to maximize exposure to sunlight for photosynthesis.